Programs & Examples On #Datediff

Date-difference will give difference in the number of days, months, years etc. between any two calendar dates. Not defined by ISO/ANSI SQL, but several vendors have similar implementations.

How to calculate DATE Difference in PostgreSQL?

This is how I usually do it. A simple number of days perspective of B minus A.

DATE_PART('day', MAX(joindate) - MIN(joindate)) as date_diff

Difference between dates in JavaScript

This answer, based on another one (link at end), is about the difference between two dates.
You can see how it works because it's simple, also it includes splitting the difference into
units of time (a function that I made) and converting to UTC to stop time zone problems.

_x000D_
_x000D_
function date_units_diff(a, b, unit_amounts) {_x000D_
    var split_to_whole_units = function (milliseconds, unit_amounts) {_x000D_
        // unit_amounts = list/array of amounts of milliseconds in a_x000D_
        // second, seconds in a minute, etc., for example "[1000, 60]"._x000D_
        time_data = [milliseconds];_x000D_
        for (i = 0; i < unit_amounts.length; i++) {_x000D_
            time_data.push(parseInt(time_data[i] / unit_amounts[i]));_x000D_
            time_data[i] = time_data[i] % unit_amounts[i];_x000D_
        }; return time_data.reverse();_x000D_
    }; if (unit_amounts == undefined) {_x000D_
        unit_amounts = [1000, 60, 60, 24];_x000D_
    };_x000D_
    var utc_a = new Date(a.toUTCString());_x000D_
    var utc_b = new Date(b.toUTCString());_x000D_
    var diff = (utc_b - utc_a);_x000D_
    return split_to_whole_units(diff, unit_amounts);_x000D_
}_x000D_
_x000D_
// Example of use:_x000D_
var d = date_units_diff(new Date(2010, 0, 1, 0, 0, 0, 0), new Date()).slice(0,-2);_x000D_
document.write("In difference: 0 days, 1 hours, 2 minutes.".replace(_x000D_
   /0|1|2/g, function (x) {return String( d[Number(x)] );} ));
_x000D_
_x000D_
_x000D_

How my code above works

A date/time difference, as milliseconds, can be calculated using the Date object:

var a = new Date(); // Current date now.
var b = new Date(2010, 0, 1, 0, 0, 0, 0); // Start of 2010.

var utc_a = new Date(a.toUTCString());
var utc_b = new Date(b.toUTCString());
var diff = (utc_b - utc_a); // The difference as milliseconds.

Then to work out the number of seconds in that difference, divide it by 1000 to convert
milliseconds to seconds, then change the result to an integer (whole number) to remove
the milliseconds (fraction part of that decimal): var seconds = parseInt(diff/1000).
Also, I could get longer units of time using the same process, for example:
- (whole) minutes, dividing seconds by 60 and changing the result to an integer,
- hours, dividing minutes by 60 and changing the result to an integer.

I created a function for doing that process of splitting the difference into
whole units of time, named split_to_whole_units, with this demo:

console.log(split_to_whole_units(72000, [1000, 60]));
// -> [1,12,0] # 1 (whole) minute, 12 seconds, 0 milliseconds.

This answer is based on this other one.

Difference in Months between two dates in JavaScript

function monthDiff(d1, d2) {
var months, d1day, d2day, d1new, d2new, diffdate,d2month,d2year,d1maxday,d2maxday;
months = (d2.getFullYear() - d1.getFullYear()) * 12;
months -= d1.getMonth() + 1;
months += d2.getMonth();
months = (months <= 0 ? 0 : months);
d1day = d1.getDate();
d2day = d2.getDate();
if(d1day > d2day)
{
    d2month = d2.getMonth();
    d2year = d2.getFullYear();
    d1new = new Date(d2year, d2month-1, d1day,0,0,0,0);
    var timeDiff = Math.abs(d2.getTime() - d1new.getTime());
          diffdate = Math.abs(Math.ceil(timeDiff / (1000 * 3600 * 24))); 
    d1new = new Date(d2year, d2month, 1,0,0,0,0);
    d1new.setDate(d1new.getDate()-1);
    d1maxday = d1new.getDate();
    months += diffdate / d1maxday;
}
else
{
      if(!(d1.getMonth() == d2.getMonth() && d1.getFullYear() == d2.getFullYear()))
    {
        months += 1;
    }
    diffdate = d2day - d1day + 1;
    d2month = d2.getMonth();
    d2year = d2.getFullYear();
    d2new = new Date(d2year, d2month + 1, 1, 0, 0, 0, 0);
    d2new.setDate(d2new.getDate()-1);
    d2maxday = d2new.getDate();
    months += diffdate / d2maxday;
}

return months;

}

SQL Server Group By Month

Restrict the dimension of the NVARCHAR to 7, supplied to CONVERT to show only "YYYY-MM"

SELECT CONVERT(NVARCHAR(7),PaymentDate,120) [Month], SUM(Amount) [TotalAmount]
FROM Payments
GROUP BY CONVERT(NVARCHAR(7),PaymentDate,120)
ORDER BY [Month]

DATEDIFF function in Oracle

We can directly subtract dates to get difference in Days.

    SET SERVEROUTPUT ON ;
    DECLARE
        V_VAR NUMBER;
    BEGIN
         V_VAR:=TO_DATE('2000-01-02', 'YYYY-MM-DD') - TO_DATE('2000-01-01', 'YYYY-MM-DD') ;
         DBMS_OUTPUT.PUT_LINE(V_VAR);
    END;

The difference in months between dates in MySQL

Try this

SELECT YEAR(end_date)*12 + MONTH(end_date) - (YEAR(start_date)*12 + MONTH(start_date))

Difference in days between two dates in Java?

I might be too late to join the game but what the heck huh? :)

Do you think this is a threading issue? How are you using the output of this method for example? OR

Can we change your code to do something as simple as:

Calendar calendar1 = Calendar.getInstance();
    Calendar calendar2 = Calendar.getInstance();
    calendar1.set(<your earlier date>);
    calendar2.set(<your current date>);
    long milliseconds1 = calendar1.getTimeInMillis();
    long milliseconds2 = calendar2.getTimeInMillis();
    long diff = milliseconds2 - milliseconds1;
    long diffSeconds = diff / 1000;
    long diffMinutes = diff / (60 * 1000);
    long diffHours = diff / (60 * 60 * 1000);
    long diffDays = diff / (24 * 60 * 60 * 1000);
    System.out.println("\nThe Date Different Example");
    System.out.println("Time in milliseconds: " + diff
 + " milliseconds.");
    System.out.println("Time in seconds: " + diffSeconds
 + " seconds.");
    System.out.println("Time in minutes: " + diffMinutes 
+ " minutes.");
    System.out.println("Time in hours: " + diffHours 
+ " hours.");
    System.out.println("Time in days: " + diffDays 
+ " days.");
  }

Date Difference in php on days?

I would recommend to use date->diff function, as in example below:

   $dStart = new DateTime('2012-07-26');
   $dEnd  = new DateTime('2012-08-26');
   $dDiff = $dStart->diff($dEnd);
   echo $dDiff->format('%r%a'); // use for point out relation: smaller/greater

see http://www.php.net/manual/en/datetime.diff.php

How to calculate age in T-SQL with years, months, and days

There is another method for calculate age is

See below table

    FirstName       LastName    DOB
    sai             krishnan    1991-11-04
    Harish          S A         1998-10-11

For finding age,you can calculate through month

  Select datediff(MONTH,DOB,getdate())/12 as dates from [Organization].[Employee]

Result will be

firstname   dates
sai         27
Harish      20

How to calculate the difference between two dates using PHP?

You can also use following code to return date diff by round fractions up $date1 = $duedate; // assign due date echo $date2 = date("Y-m-d"); // current date $ts1 = strtotime($date1); $ts2 = strtotime($date2); $seconds_diff = $ts1 - $ts2; echo $datediff = ceil(($seconds_diff/3600)/24); // return in days

If you use floor method of php instead of ceil it will return you the round fraction down. Please check the difference here, some times if your staging servers timezone is different then the live site time zone in that case you may get different results so change the conditions accordingly.

Date difference in years using C#

Maybe this will be helpful for answering the question: Count of days in given year,

new DateTime(anyDate.Year, 12, 31).DayOfYear //will include leap years too

Regarding DateTime.DayOfYear Property.

How to convert number of minutes to hh:mm format in TSQL?

I'm not sure these are the best options but they'll definitely get the job done:

declare @durations table
(
    Duration int
)

Insert into @durations(Duration)
values(60),(80),(90),(150),(180),(1000)

--Option 1 - Manually concatenate the values together
select right('0' + convert(varchar,Duration / 60),2) + ':' + right('0' + convert(varchar,Duration % 60),2)
from @Durations

--Option 2 - Make use of the time variable available since SQL Server 2008
select left(convert(time,DATEADD(minute,Duration,0)),5)
from @durations

GO

Number of days between past date and current date in Google spreadsheet

DAYS360 does not calculate what you want, i.e. the number of days passed between the two dates. Use simple subtraction (-) or MINUS(). I made an updated copy of @DrCord’s sample spreadsheet to illustrate this.

Are you SURE you want DAYS360? That is a specialized function used in the financial sector to simplify calculations for bonds. It assumes a 360 day year, with 12 months of 30 days each. If you really want actual days, you'll lose 6 days each year. [source]

Calculate relative time in C#

@Jeff

var ts = new TimeSpan(DateTime.UtcNow.Ticks - dt.Ticks);

Doing a subtraction on DateTime returns a TimeSpan anyway.

So you can just do

(DateTime.UtcNow - dt).TotalSeconds

I'm also surprised to see the constants multiplied-out by hand and then comments added with the multiplications in. Was that some misguided optimisation?

Difference between two DateTimes C#?

The time difference b/w to time will be shown use this method.

 private void HoursCalculator()
    {
        var t1 = txtfromtime.Text.Trim();
        var t2 = txttotime.Text.Trim();
        var Fromtime = t1.Substring(6);
        var Totime = t2.Substring(6);
        if (Fromtime == "M")
        {
             Fromtime = t1.Substring(5);
        }
        if (Totime == "M")
        {
            Totime = t2.Substring(5);
        }

        if (Fromtime=="PM" && Totime=="AM" )
        {
            var dt1 = DateTime.Parse("1900-01-01 " + txtfromtime.Text.Trim());
            var dt2 = DateTime.Parse("1900-01-02 " + txttotime.Text.Trim());
            var t = dt1.Subtract(dt2);
            //int temp = Convert.ToInt32(t.Hours);
            //temp = temp / 2;
            lblHours.Text =t.Hours.ToString() + ":" + t.Minutes.ToString();

        }
        else if (Fromtime == "AM" && Totime == "PM")
        {
            var dt1 = DateTime.Parse("1900-01-01 " + txtfromtime.Text.Trim());
            var dt2 = DateTime.Parse("1900-01-01 " + txttotime.Text.Trim());
            TimeSpan t = (dt2.Subtract(dt1));
            lblHours.Text = t.Hours.ToString() + ":" + t.Minutes.ToString();
        }
        else
        {
            var dt1 = DateTime.Parse("1900-01-01 " + txtfromtime.Text.Trim());
            var dt2 = DateTime.Parse("1900-01-01 " + txttotime.Text.Trim());
            TimeSpan t = (dt2.Subtract(dt1));
            lblHours.Text = t.Hours.ToString() + ":" + t.Minutes.ToString();
        }
    }

use your field id's

var t1 captures a value of 4:00AM

check this code may be helpful to someone.

How to compare two dates to find time difference in SQL Server 2005, date manipulation

If you trying to get worked hours with some accuracy, try this (tested in SQL Server 2016)

SELECT DATEDIFF(MINUTE,job_start, job_end)/60.00;

Various DATEDIFF functionalities are:

SELECT DATEDIFF(year,        '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(quarter,     '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(month,       '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(dayofyear,   '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(day,         '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(week,        '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(hour,        '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(minute,      '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(second,      '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');
SELECT DATEDIFF(millisecond, '2005-12-31 23:59:59.9999999', '2006-01-01 00:00:00.0000000');

Ref: https://docs.microsoft.com/en-us/sql/t-sql/functions/datediff-transact-sql?view=sql-server-2017

How do I check the difference, in seconds, between two dates?

if you want to compute differences between two known dates, use total_seconds like this:

import datetime as dt

a = dt.datetime(2013,12,30,23,59,59)
b = dt.datetime(2013,12,31,23,59,59)

(b-a).total_seconds()

86400.0

#note that seconds doesn't give you what you want:
(b-a).seconds

0

Difference between two dates in years, months, days in JavaScript

Yet another solution, based on some PHP code. The strtotime function, also based on PHP, can be found here: http://phpjs.org/functions/strtotime/.

Date.dateDiff = function(d1, d2) {
    d1 /= 1000;
    d2 /= 1000;
    if (d1 > d2) d2 = [d1, d1 = d2][0];

    var diffs = {
        year: 0,
        month: 0,
        day: 0,
        hour: 0,
        minute: 0,
        second: 0
    }

    $.each(diffs, function(interval) {
        while (d2 >= (d3 = Date.strtotime('+1 '+interval, d1))) {
            d1 = d3;
            ++diffs[interval];
        }
    });

    return diffs;
};

Usage:

> d1 = new Date(2000, 0, 1)
Sat Jan 01 2000 00:00:00 GMT+0100 (CET)

> d2 = new Date(2013, 9, 6)
Sun Oct 06 2013 00:00:00 GMT+0200 (CEST)

> Date.dateDiff(d1, d2)
Object {
  day: 5
  hour: 0
  minute: 0
  month: 9
  second: 0
  year: 13
}

Run Excel Macro from Outside Excel Using VBScript From Command Line

Since my related question was removed by a righteous hand after I had killed the whole day searching how to beat the "macro not found or disabled" error, posting here the only syntax that worked for me (application.run didn't, no matter what I tried)

Set objExcel = CreateObject("Excel.Application")

' Didn't run this way from the Modules
'objExcel.Application.Run "c:\app\Book1.xlsm!Sub1"
' Didn't run this way either from the Sheet
'objExcel.Application.Run "c:\app\Book1.xlsm!Sheet1.Sub1"
' Nor did it run from a named Sheet
'objExcel.Application.Run "c:\app\Book1.xlsm!Named_Sheet.Sub1"

' Only ran like this (from the Module1)

Set objWorkbook = objExcel.Workbooks.Open("c:\app\Book1.xlsm")
objExcel.Run "Sub1"

Excel 2010, Win 7

Use dynamic variable names in `dplyr`

After a lot of trial and error, I found the pattern UQ(rlang::sym("some string here"))) really useful for working with strings and dplyr verbs. It seems to work in a lot of surprising situations.

Here's an example with mutate. We want to create a function that adds together two columns, where you pass the function both column names as strings. We can use this pattern, together with the assignment operator :=, to do this.

## Take column `name1`, add it to column `name2`, and call the result `new_name`
mutate_values <- function(new_name, name1, name2){
  mtcars %>% 
    mutate(UQ(rlang::sym(new_name)) :=  UQ(rlang::sym(name1)) +  UQ(rlang::sym(name2)))
}
mutate_values('test', 'mpg', 'cyl')

The pattern works with other dplyr functions as well. Here's filter:

## filter a column by a value 
filter_values <- function(name, value){
  mtcars %>% 
    filter(UQ(rlang::sym(name)) != value)
}
filter_values('gear', 4)

Or arrange:

## transform a variable and then sort by it 
arrange_values <- function(name, transform){
  mtcars %>% 
    arrange(UQ(rlang::sym(name)) %>%  UQ(rlang::sym(transform)))
}
arrange_values('mpg', 'sin')

For select, you don't need to use the pattern. Instead you can use !!:

## select a column 
select_name <- function(name){
  mtcars %>% 
    select(!!name)
}
select_name('mpg')

Python - Check If Word Is In A String

if 'seek' in 'those who seek shall find':
    print('Success!')

but keep in mind that this matches a sequence of characters, not necessarily a whole word - for example, 'word' in 'swordsmith' is True. If you only want to match whole words, you ought to use regular expressions:

import re

def findWholeWord(w):
    return re.compile(r'\b({0})\b'.format(w), flags=re.IGNORECASE).search

findWholeWord('seek')('those who seek shall find')    # -> <match object>
findWholeWord('word')('swordsmith')                   # -> None

How to return a result from a VBA function

For non-object return types, you have to assign the value to the name of your function, like this:

Public Function test() As Integer
    test = 1
End Function

Example usage:

Dim i As Integer
i = test()

If the function returns an Object type, then you must use the Set keyword like this:

Public Function testRange() As Range
    Set testRange = Range("A1")
End Function

Example usage:

Dim r As Range
Set r = testRange()

Note that assigning a return value to the function name does not terminate the execution of your function. If you want to exit the function, then you need to explicitly say Exit Function. For example:

Function test(ByVal justReturnOne As Boolean) As Integer
    If justReturnOne Then
        test = 1
        Exit Function
    End If
    'more code...
    test = 2
End Function

Documentation: http://msdn.microsoft.com/en-us/library/office/gg264233%28v=office.14%29.aspx

git clone from another directory

I am using git-bash in windows.The simplest way is to change the path address to have the forward slashes:

git clone C:/Dev/proposed 

P.S: Start the git-bash on the destination folder.

Path used in clone ---> c:/Dev/proposed

Original path in windows ---> c:\Dev\proposed

Simple way to unzip a .zip file using zlib

Minizip does have an example programs to demonstrate its usage - the files are called minizip.c and miniunz.c.

Update: I had a few minutes so I whipped up this quick, bare bones example for you. It's very smelly C, and I wouldn't use it without major improvements. Hopefully it's enough to get you going for now.

// uzip.c - Simple example of using the minizip API.
// Do not use this code as is! It is educational only, and probably
// riddled with errors and leaks!
#include <stdio.h>
#include <string.h>

#include "unzip.h"

#define dir_delimter '/'
#define MAX_FILENAME 512
#define READ_SIZE 8192

int main( int argc, char **argv )
{
    if ( argc < 2 )
    {
        printf( "usage:\n%s {file to unzip}\n", argv[ 0 ] );
        return -1;
    }

    // Open the zip file
    unzFile *zipfile = unzOpen( argv[ 1 ] );
    if ( zipfile == NULL )
    {
        printf( "%s: not found\n" );
        return -1;
    }

    // Get info about the zip file
    unz_global_info global_info;
    if ( unzGetGlobalInfo( zipfile, &global_info ) != UNZ_OK )
    {
        printf( "could not read file global info\n" );
        unzClose( zipfile );
        return -1;
    }

    // Buffer to hold data read from the zip file.
    char read_buffer[ READ_SIZE ];

    // Loop to extract all files
    uLong i;
    for ( i = 0; i < global_info.number_entry; ++i )
    {
        // Get info about current file.
        unz_file_info file_info;
        char filename[ MAX_FILENAME ];
        if ( unzGetCurrentFileInfo(
            zipfile,
            &file_info,
            filename,
            MAX_FILENAME,
            NULL, 0, NULL, 0 ) != UNZ_OK )
        {
            printf( "could not read file info\n" );
            unzClose( zipfile );
            return -1;
        }

        // Check if this entry is a directory or file.
        const size_t filename_length = strlen( filename );
        if ( filename[ filename_length-1 ] == dir_delimter )
        {
            // Entry is a directory, so create it.
            printf( "dir:%s\n", filename );
            mkdir( filename );
        }
        else
        {
            // Entry is a file, so extract it.
            printf( "file:%s\n", filename );
            if ( unzOpenCurrentFile( zipfile ) != UNZ_OK )
            {
                printf( "could not open file\n" );
                unzClose( zipfile );
                return -1;
            }

            // Open a file to write out the data.
            FILE *out = fopen( filename, "wb" );
            if ( out == NULL )
            {
                printf( "could not open destination file\n" );
                unzCloseCurrentFile( zipfile );
                unzClose( zipfile );
                return -1;
            }

            int error = UNZ_OK;
            do    
            {
                error = unzReadCurrentFile( zipfile, read_buffer, READ_SIZE );
                if ( error < 0 )
                {
                    printf( "error %d\n", error );
                    unzCloseCurrentFile( zipfile );
                    unzClose( zipfile );
                    return -1;
                }

                // Write data to file.
                if ( error > 0 )
                {
                    fwrite( read_buffer, error, 1, out ); // You should check return of fwrite...
                }
            } while ( error > 0 );

            fclose( out );
        }

        unzCloseCurrentFile( zipfile );

        // Go the the next entry listed in the zip file.
        if ( ( i+1 ) < global_info.number_entry )
        {
            if ( unzGoToNextFile( zipfile ) != UNZ_OK )
            {
                printf( "cound not read next file\n" );
                unzClose( zipfile );
                return -1;
            }
        }
    }

    unzClose( zipfile );

    return 0;
}

I built and tested it with MinGW/MSYS on Windows like this:

contrib/minizip/$ gcc -I../.. -o unzip uzip.c unzip.c ioapi.c ../../libz.a
contrib/minizip/$ ./unzip.exe /j/zlib-125.zip

How to use ? : if statements with Razor and inline code blocks

This should work:

<span class="vote-up@(puzzle.UserVote == VoteType.Up ? "-selected" : "")">Vote Up</span>

jQuery - find child with a specific class

I'm not sure if I understand your question properly, but it shouldn't matter if this div is a child of some other div. You can simply get text from all divs with class bgHeaderH2 by using following code:

$(".bgHeaderH2").text();

How can you search Google Programmatically Java API

Indeed there is an API to search google programmatically. The API is called google custom search. For using this API, you will need an Google Developer API key and a cx key. A simple procedure for accessing google search from java program is explained in my blog.

Now dead, here is the Wayback Machine link.

Last executed queries for a specific database

This works for me to find queries on any database in the instance. I'm sysadmin on the instance (check your privileges):

SELECT deqs.last_execution_time AS [Time], dest.text AS [Query], dest.*
FROM sys.dm_exec_query_stats AS deqs
CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest
WHERE dest.dbid = DB_ID('msdb')
ORDER BY deqs.last_execution_time DESC

This is the same answer that Aaron Bertrand provided but it wasn't placed in an answer.

Using "Object.create" instead of "new"

There is really no advantage in using Object.create(...) over new object.

Those advocating this method generally state rather ambiguous advantages: "scalability", or "more natural to JavaScript" etc.

However, I have yet to see a concrete example that shows that Object.create has any advantages over using new. On the contrary there are known problems with it. Sam Elsamman describes what happens when there are nested objects and Object.create(...) is used:

var Animal = {
    traits: {},
}
var lion = Object.create(Animal);
lion.traits.legs = 4;
var bird = Object.create(Animal);
bird.traits.legs = 2;
alert(lion.traits.legs) // shows 2!!!

This occurs because Object.create(...) advocates a practice where data is used to create new objects; here the Animal datum becomes part of the prototype of lion and bird, and causes problems as it is shared. When using new the prototypal inheritance is explicit:

function Animal() {
    this.traits = {};
}

function Lion() { }
Lion.prototype = new Animal();
function Bird() { }
Bird.prototype = new Animal();

var lion = new Lion();
lion.traits.legs = 4;
var bird = new Bird();
bird.traits.legs = 2;
alert(lion.traits.legs) // now shows 4

Regarding, the optional property attributes that are passed into Object.create(...), these can be added using Object.defineProperties(...).

Getting data from selected datagridview row and which event?

You can try this click event

private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
    if (e.RowIndex >= 0)
    {
        DataGridViewRow row = this.dataGridView1.Rows[e.RowIndex];
        Eid_txt.Text = row.Cells["Employee ID"].Value.ToString();
        Name_txt.Text = row.Cells["First Name"].Value.ToString();
        Surname_txt.Text = row.Cells["Last Name"].Value.ToString();

How to downgrade from Internet Explorer 11 to Internet Explorer 10?

Go to installed updates and just uninstall Internet Explorer 11 Windows update. It works for me.

How do I install an R package from source?

Download the source package, open Terminal.app, navigate to the directory where you currently have the file, and then execute:

R CMD INSTALL RJSONIO_0.2-3.tar.gz

Do note that this will only succeed when either: a) the package does not need compilation or b) the needed system tools for compilation are present. See: https://cran.r-project.org/bin/macosx/tools/

How to detect a mobile device with JavaScript?

Simply use DeviceDetection

deviceDetection.deviceType // phone | tablet according to device

SHA512 vs. Blowfish and Bcrypt

I agree with erickson's answer, with one caveat: for password authentication purposes, bcrypt is far better than a single iteration of SHA-512 - simply because it is far slower. If you don't get why slowness is an advantage in this particular game, read the article you linked to again (scroll down to "Speed is exactly what you don’t want in a password hash function.").

You can of course build a secure password hashing algorithm around SHA-512 by iterating it thousands of times, just like the way PHK's MD5 algorithm works. Ulrich Drepper did exactly this, for glibc's crypt(). There's no particular reason to do this, though, if you already have a tested bcrypt implementation available.

Oracle: SQL query that returns rows with only numeric values

If you use Oracle 10 or higher you can use regexp functions as codaddict suggested. In earlier versions translate function will help you:

select * from tablename  where translate(x, '.1234567890', '.') is null;

More info about Oracle translate function can be found here or in official documentation "SQL Reference"

UPD: If you have signs or spaces in your numbers you can add "+-" characters to the second parameter of translate function.

How do I concatenate strings with variables in PowerShell?

This will get all dll files and filter ones that match a regex of your directory structure.

Get-ChildItem C:\code -Recurse -filter "*.dll" | where { $_.directory -match 'C:\\code\\myproj.\\bin\\debug'}

If you just want the path, not the object you can add | select fullname to the end like this:

Get-ChildItem C:\code -Recurse -filter "*.dll" | where { $_.directory -match 'C:\\code\\myproj.\\bin\\debug'} | select fullname

TypeScript or JavaScript type casting

You can cast like this:

return this.createMarkerStyle(<MarkerSymbolInfo> symbolInfo);

Or like this if you want to be compatible with tsx mode:

return this.createMarkerStyle(symbolInfo as MarkerSymbolInfo);

Just remember that this is a compile-time cast, and not a runtime cast.

Combining node.js and Python

I'd recommend using some work queue using, for example, the excellent Gearman, which will provide you with a great way to dispatch background jobs, and asynchronously get their result once they're processed.

The advantage of this, used heavily at Digg (among many others) is that it provides a strong, scalable and robust way to make workers in any language to speak with clients in any language.

What are the parameters for the number Pipe - Angular 2

'1.0-0' will give you zero decimal places i.e. no decimals. e.g.$500

Basic CSS - how to overlay a DIV with semi-transparent DIV on top

Like the answer previous, but I'd put ::before, just for stacking purposes. If you want to include text over the overlay (a common use case), using ::before will should fix that.

.dimmed {
  position: relative;
}

.dimmed:before {
  content: " ";
  z-index: 10;
  display: block;
  position: absolute;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.5);
}

How does "make" app know default target to build if no target is specified?

To save others a few seconds, and to save them from having to read the manual, here's the short answer. Add this to the top of your make file:

.DEFAULT_GOAL := mytarget

mytarget will now be the target that is run if "make" is executed and no target is specified.

If you have an older version of make (<= 3.80), this won't work. If this is the case, then you can do what anon mentions, simply add this to the top of your make file:

.PHONY: default
default: mytarget ;

References: https://www.gnu.org/software/make/manual/html_node/How-Make-Works.html

Removing elements from array Ruby

[1,3].inject([1,1,1,2,2,3]) do |memo,element|
  memo.tap do |memo|
    i = memo.find_index(e)
    memo.delete_at(i) if i
  end
end

How to check if element in groovy array/hash/collection/list?

IMPORTANT Gotcha for using .contains() on a Collection of Objects, such as Domains. If the Domain declaration contains a EqualsAndHashCode, or some other equals() implementation to determine if those Ojbects are equal, and you've set it like this...

import groovy.transform.EqualsAndHashCode
@EqualsAndHashCode(includes = "settingNameId, value")

then the .contains(myObjectToCompareTo) will evaluate the data in myObjectToCompareTo with the data for each Object instance in the Collection. So, if your equals method isn't up to snuff, as mine was not, you might see unexpected results.

Calculating the angle between the line defined by two points

in android i did this using kotlin:

private fun angleBetweenPoints(a: PointF, b: PointF): Double {
        val deltaY = abs(b.y - a.y)
        val deltaX = abs(b.x - a.x)
        return Math.toDegrees(atan2(deltaY.toDouble(), deltaX.toDouble()))
    }

Overloading operators in typedef structs (c++)

The breakdown of your declaration and its members is somewhat littered:

Remove the typedef

The typedef is neither required, not desired for class/struct declarations in C++. Your members have no knowledge of the declaration of pos as-written, which is core to your current compilation failure.

Change this:

typedef struct {....} pos;

To this:

struct pos { ... };

Remove extraneous inlines

You're both declaring and defining your member operators within the class definition itself. The inline keyword is not needed so long as your implementations remain in their current location (the class definition)


Return references to *this where appropriate

This is related to an abundance of copy-constructions within your implementation that should not be done without a strong reason for doing so. It is related to the expression ideology of the following:

a = b = c;

This assigns c to b, and the resulting value b is then assigned to a. This is not equivalent to the following code, contrary to what you may think:

a = c;
b = c;

Therefore, your assignment operator should be implemented as such:

pos& operator =(const pos& a)
{
    x = a.x;
    y = a.y;
    return *this;
}

Even here, this is not needed. The default copy-assignment operator will do the above for you free of charge (and code! woot!)

Note: there are times where the above should be avoided in favor of the copy/swap idiom. Though not needed for this specific case, it may look like this:

pos& operator=(pos a) // by-value param invokes class copy-ctor
{
    this->swap(a);
    return *this;
}

Then a swap method is implemented:

void pos::swap(pos& obj)
{
    // TODO: swap object guts with obj
}

You do this to utilize the class copy-ctor to make a copy, then utilize exception-safe swapping to perform the exchange. The result is the incoming copy departs (and destroys) your object's old guts, while your object assumes ownership of there's. Read more the copy/swap idiom here, along with the pros and cons therein.


Pass objects by const reference when appropriate

All of your input parameters to all of your members are currently making copies of whatever is being passed at invoke. While it may be trivial for code like this, it can be very expensive for larger object types. An exampleis given here:

Change this:

bool operator==(pos a) const{
    if(a.x==x && a.y== y)return true;
    else return false;
}

To this: (also simplified)

bool operator==(const pos& a) const
{
    return (x == a.x && y == a.y);
}

No copies of anything are made, resulting in more efficient code.


Finally, in answering your question, what is the difference between a member function or operator declared as const and one that is not?

A const member declares that invoking that member will not modifying the underlying object (mutable declarations not withstanding). Only const member functions can be invoked against const objects, or const references and pointers. For example, your operator +() does not modify your local object and thus should be declared as const. Your operator =() clearly modifies the local object, and therefore the operator should not be const.


Summary

struct pos
{
    int x;
    int y;

    // default + parameterized constructor
    pos(int x=0, int y=0) 
        : x(x), y(y)
    {
    }

    // assignment operator modifies object, therefore non-const
    pos& operator=(const pos& a)
    {
        x=a.x;
        y=a.y;
        return *this;
    }

    // addop. doesn't modify object. therefore const.
    pos operator+(const pos& a) const
    {
        return pos(a.x+x, a.y+y);
    }

    // equality comparison. doesn't modify object. therefore const.
    bool operator==(const pos& a) const
    {
        return (x == a.x && y == a.y);
    }
};

EDIT OP wanted to see how an assignment operator chain works. The following demonstrates how this:

a = b = c;

Is equivalent to this:

b = c;
a = b;

And that this does not always equate to this:

a = c;
b = c;

Sample code:

#include <iostream>
#include <string>
using namespace std;

struct obj
{
    std::string name;
    int value;

    obj(const std::string& name, int value)
        : name(name), value(value)
    {
    }

    obj& operator =(const obj& o)
    {
        cout << name << " = " << o.name << endl;
        value = (o.value+1); // note: our value is one more than the rhs.
        return *this;
    }    
};

int main(int argc, char *argv[])
{

    obj a("a", 1), b("b", 2), c("c", 3);

    a = b = c;
    cout << "a.value = " << a.value << endl;
    cout << "b.value = " << b.value << endl;
    cout << "c.value = " << c.value << endl;

    a = c;
    b = c;
    cout << "a.value = " << a.value << endl;
    cout << "b.value = " << b.value << endl;
    cout << "c.value = " << c.value << endl;

    return 0;
}

Output

b = c
a = b
a.value = 5
b.value = 4
c.value = 3
a = c
b = c
a.value = 4
b.value = 4
c.value = 3

DateTime vs DateTimeOffset

There's a few places where DateTimeOffset makes sense. One is when you're dealing with recurring events and daylight savings time. Let's say I want to set an alarm to go off at 9am every day. If I use the "store as UTC, display as local time" rule, then the alarm will be going off at a different time when daylight savings time is in effect.

There are probably others, but the above example is actually one that I've run into in the past (this was before the addition of DateTimeOffset to the BCL - my solution at the time was to explicitly store the time in the local timezone, and save the timezone information along side it: basically what DateTimeOffset does internally).

How to add local .jar file dependency to build.gradle file?

The accepted answer is good, however, I would have needed various library configurations within my multi-project Gradle build to use the same 3rd-party Java library.

Adding '$rootProject.projectDir' to the 'dir' path element within my 'allprojects' closure meant each sub-project referenced the same 'libs' directory, and not a version local to that sub-project:

//gradle.build snippet
allprojects {
    ...

    repositories {
        //All sub-projects will now refer to the same 'libs' directory
        flatDir {
            dirs "$rootProject.projectDir/libs"
        }
        mavenCentral()
    }

    ...
}

EDIT by Quizzie: changed "${rootProject.projectDir}" to "$rootProject.projectDir" (works in the newest Gradle version).

What does the Java assert keyword do, and when should it be used?

A lot of good answers explaining what the assert keyword does, but few answering the real question, "when should the assert keyword be used in real life?"

The answer: almost never.

Assertions, as a concept, are wonderful. Good code has lots of if (...) throw ... statements (and their relatives like Objects.requireNonNull and Math.addExact). However, certain design decisions have greatly limited the utility of the assert keyword itself.

The driving idea behind the assert keyword is premature optimization, and the main feature is being able to easily turn off all checks. In fact, the assert checks are turned off by default.

However, it is critically important that invariant checks continue to be done in production. This is because perfect test coverage is impossible, and all production code will have bugs which assertions should help to diagnose and mitigate.

Therefore, the use of if (...) throw ... should be preferred, just as it is required for checking parameter values of public methods and for throwing IllegalArgumentException.

Occasionally, one might be tempted to write an invariant check that does take an undesirably long time to process (and is called often enough for it to matter). However, such checks will slow down testing which is also undesirable. Such time-consuming checks are usually written as unit tests. Nevertheless, it may sometimes make sense to use assert for this reason.

Do not use assert simply because it is cleaner and prettier than if (...) throw ... (and I say that with great pain, because I like clean and pretty). If you just cannot help yourself, and can control how your application is launched, then feel free to use assert but always enable assertions in production. Admittedly, this is what I tend to do. I am pushing for a lombok annotation that will cause assert to act more like if (...) throw .... Vote for it here.

(Rant: the JVM devs were a bunch of awful, prematurely optimizing coders. That is why you hear about so many security issues in the Java plugin and JVM. They refused to include basic checks and assertions in production code, and we are continuing to pay the price.)

Is PowerShell ready to replace my Cygwin shell on Windows?

I found PowerShell programming to be not worth the effort.

I have several years of experience with shell scripting under Unix, but I found it enormously difficult to do much of anything with PowerShell.

It seems like many functions require you to interrogate the Windows Management Interface and issue SQL-like commands to get the information you need.

For example, I wanted to write a script to remove all files with a specific suffix from a directory tree. Under Unix, this would be a simple ...

find . -name \*.xyz -exec rm {} \;

After a couple of hours dicking around with Scripting.FileSystemObject and WScript.Shell and issuing "SELECT * FROM Win32_ShortcutFile WHERE Drive = '" & drive & "' AND Path = '" & searchFolder & "'", I finally gave up and settled for Windows Explorer's Search command and just do it manually. There's probably some way to do what I wanted, but I didn't see anything obvious and all the examples on the MSDN site were so trivial as to be worthless.

EDIT Heh, of course as soon as I wrote this I poked around some more and found what I had been missing: the -recurse option to the remove-item command is faulty (revealed if you use get-help remove-item -detailed).

I had been trying "remove-item -filter '* .xyz' -recurse" and it wasn't working, so I gave up on it.

Turns out you need to use get-childitem -filter '*.xyz' -recurse | remove-item

Can you change what a symlink points to after it is created?

Wouldn't unlinking it and creating the new one do the same thing in the end anyway?

How to urlencode data for curl command?

Here is the pure BASH answer.

rawurlencode() {
  local string="${1}"
  local strlen=${#string}
  local encoded=""
  local pos c o

  for (( pos=0 ; pos<strlen ; pos++ )); do
     c=${string:$pos:1}
     case "$c" in
        [-_.~a-zA-Z0-9] ) o="${c}" ;;
        * )               printf -v o '%%%02x' "'$c"
     esac
     encoded+="${o}"
  done
  echo "${encoded}"    # You can either set a return variable (FASTER) 
  REPLY="${encoded}"   #+or echo the result (EASIER)... or both... :p
}

You can use it in two ways:

easier:  echo http://url/q?=$( rawurlencode "$args" )
faster:  rawurlencode "$args"; echo http://url/q?${REPLY}

[edited]

Here's the matching rawurldecode() function, which - with all modesty - is awesome.

# Returns a string in which the sequences with percent (%) signs followed by
# two hex digits have been replaced with literal characters.
rawurldecode() {

  # This is perhaps a risky gambit, but since all escape characters must be
  # encoded, we can replace %NN with \xNN and pass the lot to printf -b, which
  # will decode hex for us

  printf -v REPLY '%b' "${1//%/\\x}" # You can either set a return variable (FASTER)

  echo "${REPLY}"  #+or echo the result (EASIER)... or both... :p
}

With the matching set, we can now perform some simple tests:

$ diff rawurlencode.inc.sh \
        <( rawurldecode "$( rawurlencode "$( cat rawurlencode.inc.sh )" )" ) \
        && echo Matched

Output: Matched

And if you really really feel that you need an external tool (well, it will go a lot faster, and might do binary files and such...) I found this on my OpenWRT router...

replace_value=$(echo $replace_value | sed -f /usr/lib/ddns/url_escape.sed)

Where url_escape.sed was a file that contained these rules:

# sed url escaping
s:%:%25:g
s: :%20:g
s:<:%3C:g
s:>:%3E:g
s:#:%23:g
s:{:%7B:g
s:}:%7D:g
s:|:%7C:g
s:\\:%5C:g
s:\^:%5E:g
s:~:%7E:g
s:\[:%5B:g
s:\]:%5D:g
s:`:%60:g
s:;:%3B:g
s:/:%2F:g
s:?:%3F:g
s^:^%3A^g
s:@:%40:g
s:=:%3D:g
s:&:%26:g
s:\$:%24:g
s:\!:%21:g
s:\*:%2A:g

Do standard windows .ini files allow comments?

I have seen comments in INI files, so yes. Please refer to this Wikipedia article. I could not find an official specification, but that is the correct syntax for comments, as many game INI files had this as I remember.

Edit

The API returns the Value and the Comment (forgot to mention this in my reply), just construct and example INI file and call the API on this (with comments) and you can see how this is returned.

CSS Layout - Dynamic width DIV

try

<div style="width:100%;">
    <div style="width:50px; float: left;"><img src="myleftimage" /></div>
    <div style="width:50px; float: right;"><img src="myrightimage" /></div>
    <div style="display:block; margin-left:auto; margin-right: auto;">Content Goes Here</div>
</div>

or

<div style="width:100%; border:2px solid #dadada;">
    <div style="width:50px; float: left;"><img src="myleftimage" /></div>
    <div style="width:50px; float: right;"><img src="myrightimage" /></div>
    <div style="display:block; margin-left:auto; margin-right: auto;">Content Goes Here</div>
<div style="clear:both"></div>    
</div>

How to disable/enable select field using jQuery?

Just simply use:

var update_pizza = function () {
     $("#pizza_kind").prop("disabled", !$('#pizza').prop('checked'));
};

update_pizza();
$("#pizza").change(update_pizza);

DEMO ?

Save a list to a .txt file

You can use inbuilt library pickle

This library allows you to save any object in python to a file

This library will maintain the format as well

import pickle
with open('/content/list_1.txt', 'wb') as fp:
    pickle.dump(list_1, fp)

you can also read the list back as an object using same library

with open ('/content/list_1.txt', 'rb') as fp:
    list_1 = pickle.load(fp)

reference : Writing a list to a file with Python

\n or \n in php echo not print

PHP only interprets escaped characters (with the exception of the escaped backslash \\ and the escaped single quote \') when in double quotes (")

This works (results in a newline):

"\n"

This does not result in a newline:

'\n'

How can I get a list of repositories 'apt-get' is checking?

All I needed was:

cd /etc/apt
nano source.list
deb http://http.kali.org/kali kali-rolling main non-free contrib
deb-src http://http.kali.org/kali kali-rolling main non-free contrib
apt upgrade && update

Source: Kali Network Repositories (/etc/apt/sources.list)

C++ Pass A String

Not very technical answer but just letting you know.

For easy stuff like printing you can define a sort of function in your preprocessors like

#define print(x) cout << x << endl

How to check whether an object is a date?

Couldn't you just use

function getFormatedDate(date) {
    if (date.isValid()) {
       var month = date.GetMonth();
    }
}

How to remove \n from a list element?

str.strip() removes the whitespace characters. you can also pass custom characters as argument to strip. The strip function removes the whitespace/custom characters on both ends of the string. lstrip() and rstrip() are left strip and right strip functions resp.

Eg:

test_str = "Vishaka\n" 
test_str = test_str.strip()

test_str's now Vishaka

How to prevent form resubmission when page is refreshed (F5 / CTRL+R)

This form.php sample shows how to use PRG correct (when form is valid or not).

  • It redirects to the same page, only when form is valid and action was performed.
  • Redirection protects form from being resubmitted on page refresh.
  • It uses session to not loose success messages you want to show when form is valid.
  • There are two buttons for testing: "Valid submit", "Invalid submit". Try both and refresh page after that.
<?php
session_start();

function doSelfRedirect()
{
  header('Location:'.$_SERVER['PHP_SELF']);
  exit;
}

function setFlashMessage($msg)
{
  $_SESSION['message'] = $msg;
}

function getFlashMessage()
{
  if (!empty($_SESSION['message'])) {
    $msg = $_SESSION['message'];
    unset($_SESSION['message']);
  } else {
    $msg = null;
  }

  return $msg;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
  // Validation primitive example.
  if (empty($_POST['valid'])) {
    $formIsValid = false;
    setFlashMessage('Invalid form submit');
  } else {
    $formIsValid = true;
  }

  if ($formIsValid) {
    // Perform any actions here.
    // ...

    // Cool!
    setFlashMessage('Form is valid. Action performed.');

    // Prevent form resubmission.
    doSelfRedirect();
  }
}
?>
<h1>Hello form</h1>

<?php if ($msg = getFlashMessage()): ?>
  <div><?= $msg ?></div>
<?php endif; ?>

<form method="post">
  <input type="text" name="foo" value="bar"><br><br>
  <button type="submit" name="invalid" value="0">Invalid submit</button>
  <button type="submit" name="valid" value="1">Valid submit</button>
</form>

How get permission for camera in android.(Specifically Marshmallow)

First check if the user has granted the permission:

if (ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA)
    == PackageManager.PERMISSION_DENIED)

Then, you could use this to request to the user:

ActivityCompat.requestPermissions(activity, new String[] {Manifest.permission.CAMERA}, requestCode);

And in Marshmallow, it will appear in a dialog

Display unescaped HTML in Vue.js

Vue by default ships with the v-html directive to show it, you bind it onto the element itself rather than using the normal moustache binding for string variables.

So for your specific example you would need:

<div id="logapp">    
    <table>
        <tbody>
            <tr v-repeat="logs">
                <td v-html="fail"></td>
                <td v-html="type"></td>
                <td v-html="description"></td>
                <td v-html="stamp"></td>
                <td v-html="id"></td>
            </tr>
        </tbody>
    </table>
</div>

Windows: XAMPP vs WampServer vs EasyPHP vs alternative

I generally install Apache + PHP + MySQL by-hand, not using any package like those you're talking about.

It's a bit more work, yes; but knowing how to install and configure your environment is great -- and useful.

The first time, you'll need maybe half a day or a day to configure those. But, at least, you'll know how to do so.

And the next times, things will be far more easy, and you'll need less time.

Else, you might want to take a look at Zend Server -- which is another package that bundles Apache + PHP + MySQL.

Or, as an alternative, don't use Windows.

If your production servers are running Linux, why not run Linux on your development machine?

And if you don't want to (or cannot) install Linux on your computer, use a Virtual Machine.

How can I style an Android Switch?

It's an awesome detailed reply by Janusz. But just for the sake of people who are coming to this page for answers, the easier way is at http://android-holo-colors.com/ (dead link) linked from Android Asset Studio

A good description of all the tools are at AndroidOnRocks.com (site offline now)

However, I highly recommend everybody to read the reply from Janusz as it will make understanding clearer. Use the tool to do stuffs real quick

Remove element of a regular array

This is a way to delete an array element, as of .Net 3.5, without copying to another array - using the same array instance with Array.Resize<T>:

public static void RemoveAt<T>(ref T[] arr, int index)
{
    for (int a = index; a < arr.Length - 1; a++)
    {
        // moving elements downwards, to fill the gap at [index]
        arr[a] = arr[a + 1];
    }
    // finally, let's decrement Array's size by one
    Array.Resize(ref arr, arr.Length - 1);
}

Sleep function in ORACLE

Seems the java procedure/function could work. But why don't you compile your function under a user like the application schema or a admin account that has this grant and just grant your developer account execute on it. That way the definer rights are used.

How to empty a list?

it turns out that with python 2.5.2, del l[:] is slightly slower than l[:] = [] by 1.1 usec.

$ python -mtimeit "l=list(range(1000))" "b=l[:];del b[:]"
10000 loops, best of 3: 29.8 usec per loop
$ python -mtimeit "l=list(range(1000))" "b=l[:];b[:] = []"
10000 loops, best of 3: 28.7 usec per loop
$ python -V
Python 2.5.2

Change a Nullable column to NOT NULL with Default Value

you need to execute two queries:

One - to add the default value to the column required

ALTER TABLE 'Table_Name` ADD DEFAULT 'value' FOR 'Column_Name'

i want add default value to Column IsDeleted as below:

Example: ALTER TABLE [dbo].[Employees] ADD Default 0 for IsDeleted

Two - to alter the column value nullable to not null

ALTER TABLE 'table_name' ALTER COLUMN 'column_name' 'data_type' NOT NULL

i want to make the column IsDeleted as not null

ALTER TABLE [dbo].[Employees] Alter Column IsDeleted BIT NOT NULL

How to implement the ReLU function in Numpy

ReLU(x) also is equal to (x+abs(x))/2

How to customize an end time for a YouTube video?

I just found out that the following works:

https://www.youtube.com/embed/[video_id]?start=[start_at_second]&end=[end_at_second]

Note: the time must be an integer number of seconds (e.g. 119, not 1m59s).

How to compile C++ under Ubuntu Linux?

Install gcc and try the video below.
Try this:
https://www.youtube.com/watch?v=A6v2Ceqy4Tk
Hope it will works for you.

Is there a way to force npm to generate package-lock.json?

In npm 6.x you can use

npm i --package-lock-only

According to https://docs.npmjs.com/cli/install.html

The --package-lock-only argument will only update the package-lock.json, instead of checking node_modules and downloading dependencies.

Bash scripting, multiple conditions in while loop

The correct options are (in increasing order of recommendation):

# Single POSIX test command with -o operator (not recommended anymore).
# Quotes strongly recommended to guard against empty or undefined variables.
while [ "$stats" -gt 300 -o "$stats" -eq 0 ]

# Two POSIX test commands joined in a list with ||.
# Quotes strongly recommended to guard against empty or undefined variables.
while [ "$stats" -gt 300 ] || [ "$stats" -eq 0 ]

# Two bash conditional expressions joined in a list with ||.
while [[ $stats -gt 300 ]] || [[ $stats -eq 0 ]]

# A single bash conditional expression with the || operator.
while [[ $stats -gt 300 || $stats -eq 0 ]]

# Two bash arithmetic expressions joined in a list with ||.
# $ optional, as a string can only be interpreted as a variable
while (( stats > 300 )) || (( stats == 0 ))

# And finally, a single bash arithmetic expression with the || operator.
# $ optional, as a string can only be interpreted as a variable
while (( stats > 300 || stats == 0 ))

Some notes:

  1. Quoting the parameter expansions inside [[ ... ]] and ((...)) is optional; if the variable is not set, -gt and -eq will assume a value of 0.

  2. Using $ is optional inside (( ... )), but using it can help avoid unintentional errors. If stats isn't set, then (( stats > 300 )) will assume stats == 0, but (( $stats > 300 )) will produce a syntax error.

jQuery rotate/transform

Simply remove the line that rotates it one degree at a time and calls the script forever.

// Animate rotation with a recursive call
setTimeout(function() { rotate(++degree); },65);

Then pass the desired value into the function... in this example 45 for 45 degrees.

$(function() {

    var $elie = $("#bkgimg");
    rotate(45);

        function rotate(degree) {
      // For webkit browsers: e.g. Chrome
           $elie.css({ WebkitTransform: 'rotate(' + degree + 'deg)'});
      // For Mozilla browser: e.g. Firefox
           $elie.css({ '-moz-transform': 'rotate(' + degree + 'deg)'});
        }

});

Change .css() to .animate() in order to animate the rotation with jQuery. We also need to add a duration for the animation, 5000 for 5 seconds. And updating your original function to remove some redundancy and support more browsers...

$(function() {

    var $elie = $("#bkgimg");
    rotate(45);

        function rotate(degree) {
            $elie.animate({
                        '-webkit-transform': 'rotate(' + degree + 'deg)',
                        '-moz-transform': 'rotate(' + degree + 'deg)',
                        '-ms-transform': 'rotate(' + degree + 'deg)',
                        '-o-transform': 'rotate(' + degree + 'deg)',
                        'transform': 'rotate(' + degree + 'deg)',
                        'zoom': 1
            }, 5000);
        }
});

EDIT: The standard jQuery CSS animation code above is not working because apparently, jQuery .animate() does not yet support the CSS3 transforms.

This jQuery plugin is supposed to animate the rotation:

http://plugins.jquery.com/project/QTransform

Using CookieContainer with WebClient class

Yes. IMHO, overriding GetWebRequest() is the best solution to WebClient's limited functionalty. Before I knew about this option, I wrote lots of really painful code at the HttpWebRequest layer because WebClient almost, but not quite, did what I needed. Derivation is much easier.

Another option is to use the regular WebClient class, but manually populate the Cookie header before making the request and then pull out the Set-Cookies header on the response. There are helper methods on the CookieContainer class which make creating and parsing these headers easier: CookieContainer.SetCookies() and CookieContainer.GetCookieHeader(), respectively.

I prefer the former approach since it's easier for the caller and requires less repetitive code than the second option. Also, the derivation approach works the same way for multiple extensibility scenarios (e.g. cookies, proxies, etc.).

DateTime.ToString() format that can be used in a filename or extension?

The below list of time format specifiers most commonly used.,

dd -- day of the month, from 01 through 31.

MM -- month, from 01 through 12.

yyyy -- year as a four-digit number.

hh -- hour, using a 12-hour clock from 01 to 12.

mm -- minute, from 00 through 59.

ss -- second, from 00 through 59.

HH -- hour, using a 24-hour clock from 00 to 23.

tt -- AM/PM designator.

Using the above you will be able to form a unique name to your file name.

Here i have provided example

string fileName = "fileName_" + DateTime.Now.ToString("MM-dd-yyyy_hh-mm-ss-tt") + ".pdf";

OR

If you don't prefer to use symbols you can try this also.,

string fileName = "fileName_" + DateTime.Now.ToString("MMddyyyyhhmmsstt") + ".pdf";

Hope this helps to someone now or in future. :)

adding css class to multiple elements

try this:

.button input, .button a {
//css here
}

That will apply the style to all a tags nested inside of <p class="button"></p>

How can I compare a date and a datetime in Python?

Here is another take, "stolen" from a comment at can't compare datetime.datetime to datetime.date ... convert the date to a datetime using this construct:

datetime.datetime(d.year, d.month, d.day)

Suggestion:

from datetime import datetime

def ensure_datetime(d):
    """
    Takes a date or a datetime as input, outputs a datetime
    """
    if isinstance(d, datetime):
        return d
    return datetime.datetime(d.year, d.month, d.day)

def datetime_cmp(d1, d2):
    """
    Compares two timestamps.  Tolerates dates.
    """
    return cmp(ensure_datetime(d1), ensure_datetime(d2))

How to get htaccess to work on MAMP

I'm using MAMP (downloaded today) and had this problem also. The issue is with this version of the MAMP stack's default httpd.conf directive around line 370. Look at httpd.conf down at around line 370 and you will find:

<Directory "/Applications/MAMP/bin/mamp">
    Options Indexes MultiViews
    AllowOverride None
    Order allow,deny
    Allow from all
</Directory>

You need to change: AllowOverride None To: AllowOverride All

how to make a countdown timer in java

import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;

public class Stopwatch {
static int interval;
static Timer timer;

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Input seconds => : ");
    String secs = sc.nextLine();
    int delay = 1000;
    int period = 1000;
    timer = new Timer();
    interval = Integer.parseInt(secs);
    System.out.println(secs);
    timer.scheduleAtFixedRate(new TimerTask() {

        public void run() {
            System.out.println(setInterval());

        }
    }, delay, period);
}

private static final int setInterval() {
    if (interval == 1)
        timer.cancel();
    return --interval;
}
}

Try this.

How do I install g++ on MacOS X?

That's the compiler that comes with Apple's XCode tools package. They've hacked on it a little, but basically it's just g++.

You can download XCode for free (well, mostly, you do have to sign up to become an ADC member, but that's free too) here: http://developer.apple.com/technology/xcode.html

Edit 2013-01-25: This answer was correct in 2010. It needs an update.

While XCode tools still has a command-line C++ compiler, In recent versions of OS X (I think 10.7 and later) have switched to clang/llvm (mostly because Apple wants all the benefits of Open Source without having to contribute back and clang is BSD licensed). Secondly, I think all you have to do to install XCode is to download it from the App store. I'm pretty sure it's free there.

So, in order to get g++ you'll have to use something like homebrew (seemingly the current way to install Open Source software on the Mac (though homebrew has a lot of caveats surrounding installing gcc using it)), fink (basically Debian's apt system for OS X/Darwin), or MacPorts (Basically, OpenBSDs ports system for OS X/Darwin) to get it.

Fink definitely has the right packages. On 2016-12-26, it had gcc 5 and gcc 6 packages.

I'm less familiar with how MacPorts works, though some initial cursory investigation indicates they have the relevant packages as well.

Why am I getting an OPTIONS request instead of a GET request?

If you're trying to POST

Make sure to JSON.stringify your form data and send as text/plain.

<form id="my-form" onSubmit="return postMyFormData();">
    <input type="text" name="name" placeholder="Your Name" required>
    <input type="email" name="email" placeholder="Your Email" required>
    <input type="submit" value="Submit My Form">
</form>

function postMyFormData() {

    var formData = $('#my-form').serializeArray();
    formData = formData.reduce(function(obj, item) {
        obj[item.name] = item.value;
        return obj;
    }, {});
    formData = JSON.stringify(formData);

    $.ajax({
        type: "POST",
        url: "https://website.com/path",
        data: formData,
        success: function() { ... },
        dataType: "text",
        contentType : "text/plain"
    });
}

How do I launch the Android emulator from the command line?

See below instructions for Ubuntu Linux with zsh:

  1. Open terminal window (CTRL+ALT+T)
  2. Run command nano ~/.zshrc to edit your profile
  3. Add following lines in the opened file:
export ANDROID_SDK_HOME="~/Android/Sdk"
alias emulator="$ANDROID_SDK_HOME/emulator/emulator"
  1. Save the file (CTRL+O, CTRL+X)
  2. Source the profile by running command source ~/.zshrc or just log out and log back in
  3. Test by running the command emulator -help in terminal

NOTE: Should be same for bash by replacing .zshrc with .bashrc

How to duplicate sys.stdout to a log file?

The print statement will call the write() method of any object you assign to sys.stdout.

I would spin up a small class to write to two places at once...

import sys

class Logger(object):
    def __init__(self):
        self.terminal = sys.stdout
        self.log = open("log.dat", "a")

    def write(self, message):
        self.terminal.write(message)
        self.log.write(message)  

sys.stdout = Logger()

Now the print statement will both echo to the screen and append to your log file:

# prints "1 2" to <stdout> AND log.dat
print "%d %d" % (1,2)

This is obviously quick-and-dirty. Some notes:

  • You probably ought to parametize the log filename.
  • You should probably revert sys.stdout to <stdout> if you won't be logging for the duration of the program.
  • You may want the ability to write to multiple log files at once, or handle different log levels, etc.

These are all straightforward enough that I'm comfortable leaving them as exercises for the reader. The key insight here is that print just calls a "file-like object" that's assigned to sys.stdout.

git visual diff between branches

Have a look at git show-branch

There's a lot you can do with core git functionality. It might be good to specify what you'd like to include in your visual diff. Most answers focus on line-by-line diffs of commits, where your example focuses on names of files affected in a given commit.

One visual that seems not to be addressed is how to see the commits that branches contain (whether in common or uniquely).

For this visual, I'm a big fan of git show-branch; it breaks out a well organized table of commits per branch back to the common ancestor. - to try it on a repo with multiple branches with divergences, just type git show-branch and check the output - for a writeup with examples, see Compare Commits Between Git Branches

Subprocess check_output returned non-zero exit status 1

The command yum that you launch was executed properly. It returns a non zero status which means that an error occured during the processing of the command. You probably want to add some argument to your yum command to fix that.

Your code could show this error this way:

import subprocess
try:
    subprocess.check_output("dir /f",shell=True,stderr=subprocess.STDOUT)
except subprocess.CalledProcessError as e:
    raise RuntimeError("command '{}' return with error (code {}): {}".format(e.cmd, e.returncode, e.output))

How to check if a string contains only numbers?

http://msdn.microsoft.com/en-us/library/f02979c7(v=VS.90).aspx

You can pass nothing if you don't need the returned integer like so

if integer.TryParse(number,nothing) then

What does CultureInfo.InvariantCulture mean?

For things like numbers (decimal points, commas in amounts), they are usually preferred in the specific culture.

A appropriate way to do this would be set it at the culture level (for German) like this:

Thread.CurrentThread.CurrentCulture.NumberFormat = new CultureInfo("de").NumberFormat;

How to use addTarget method in swift 3

Try this with Swift 3

button.addTarget(self, action:#selector(ClassName.handleRegister(sender:)), for: .touchUpInside)

Good luck!

Detect if an element is visible with jQuery

You're looking for:

.is(':visible')

Although you should probably change your selector to use jQuery considering you're using it in other places anyway:

if($('#testElement').is(':visible')) {
    // Code
}

It is important to note that if any one of a target element's parent elements are hidden, then .is(':visible') on the child will return false (which makes sense).

jQuery 3

:visible has had a reputation for being quite a slow selector as it has to traverse up the DOM tree inspecting a bunch of elements. There's good news for jQuery 3, however, as this post explains (Ctrl + F for :visible):

Thanks to some detective work by Paul Irish at Google, we identified some cases where we could skip a bunch of extra work when custom selectors like :visible are used many times in the same document. That particular case is up to 17 times faster now!

Keep in mind that even with this improvement, selectors like :visible and :hidden can be expensive because they depend on the browser to determine whether elements are actually displaying on the page. That may require, in the worst case, a complete recalculation of CSS styles and page layout! While we don’t discourage their use in most cases, we recommend testing your pages to determine if these selectors are causing performance issues.


Expanding even further to your specific use case, there is a built in jQuery function called $.fadeToggle():

function toggleTestElement() {
    $('#testElement').fadeToggle('fast');
}

React / JSX Dynamic Component Name

Suspose we wish to access various views with dynamic component loading.The following code gives a working example of how to accomplish this by using a string parsed from the search string of a url.

Lets assume we want to access a page 'snozberrys' with two unique views using these url paths:

'http://localhost:3000/snozberrys?aComponent'

and

'http://localhost:3000/snozberrys?bComponent'

we define our view's controller like this:

import React, { Component } from 'react';
import ReactDOM from 'react-dom'
import {
  BrowserRouter as Router,
  Route
} from 'react-router-dom'
import AComponent from './AComponent.js';
import CoBComponent sole from './BComponent.js';

const views = {
  aComponent: <AComponent />,
  console: <BComponent />
}

const View = (props) => {
  let name = props.location.search.substr(1);
  let view = views[name];
  if(view == null) throw "View '" + name + "' is undefined";
  return view;
}

class ViewManager extends Component {
  render() {
    return (
      <Router>
        <div>
          <Route path='/' component={View}/>
        </div>
      </Router>
    );
  }
}

export default ViewManager

ReactDOM.render(<ViewManager />, document.getElementById('root'));

Java out.println() how is this possible?

static imports do the trick:

import static java.lang.System.out;

or alternatively import every static method and field using

import static java.lang.System.*;

Addendum by @Steve C: note that @sfussenegger said this in a comment on my Answer.

"Using such a static import of System.out isn't suited for more than simple run-once code."

So please don't imagine that he (or I) think that this solution is Good Practice.

build maven project with propriatery libraries included

You could either add the jar to your project and mess around with the maven-assembly-plugin, or add the jar to your local repository:

mvn install:install-file -Dfile=<path-to-file> -DgroupId=<group-id> -DartifactId=<artifact-id> -Dversion=<version> -Dpackaging=<packaging> -DgeneratePom=true

Where: <path-to-file>  the path to the file to load
       <group-id>      the group that the file should be registered under
       <artifact-id>   the artifact name for the file
       <version>       the version of the file
       <packaging>     the packaging of the file e.g. jar

What is a .NET developer?

I'd say the minimum would be to

  • know one of the .Net Languages (C#, VB.NET, etc.)
  • know the basic working of the .Net runtime
  • know and understand the core parts of the .Net class libraries
  • have an understanding about what additional classes and functions are available as part of the .Net class libraries

Javascript array search and remove string?

You have to write you own remove. You can loop over the array, grab the index of the item you want to remove, and use splice to remove it.

Alternatively, you can create a new array, loop over the current array, and if the current object doesn't match what you want to remove, put it in a new array.

How to print jquery object/array

What you have from the server is a string like below:

var data = '[{"id":"197","category":"Damskie"},{"id":"198","category":"M\u0119skie"}]';

Then you can use JSON.parse function to change it to an object. Then you access the category like below:

var dataObj = JSON.parse(data);

console.log(dataObj[0].category); //will return Damskie
console.log(dataObj[1].category); //will return Meskie

What does the Visual Studio "Any CPU" target mean?

I think most of the important stuff has been said, but I just thought I'd add one thing: If you compile as Any CPU and run on an x64 platform, then you won't be able to load 32-bit DLL files, because your application wasn't started in WoW64, but those DLL files need to run there.

If you compile as x86, then the x64 system will run your application in WoW64, and you'll be able to load 32-bit DLL files.

So I think you should choose "Any CPU" if your dependencies can run in either environment, but choose x86 if you have 32-bit dependencies. This article from Microsoft explains this a bit:

/CLRIMAGETYPE (Specify Type of CLR Image)

Incidentally, this other Microsoft documentation agrees that x86 is usually a more portable choice:

Choosing x86 is generally the safest configuration for an app package since it will run on nearly every device. On some devices, an app package with the x86 configuration won't run, such as the Xbox or some IoT Core devices. However, for a PC, an x86 package is the safest choice and has the largest reach for device deployment. A substantial portion of Windows 10 devices continue to run the x86 version of Windows.

Split a string by a delimiter in python

You can use the str.split method: string.split('__')

>>> "MATCHES__STRING".split("__")
['MATCHES', 'STRING']

Using gdb to single-step assembly code outside specified executable causes error "cannot find bounds of current function"

The most useful thing you can do here is display/i $pc, before using stepi as already suggested in R Samuel Klatchko's answer. This tells gdb to disassemble the current instruction just before printing the prompt each time; then you can just keep hitting Enter to repeat the stepi command.

(See my answer to another question for more detail - the context of that question was different, but the principle is the same.)

JPA OneToMany and ManyToOne throw: Repeated column in mapping for entity column (should be mapped with insert="false" update="false")

You should never use the unidirectional @OneToMany annotation because:

  1. It generates inefficient SQL statements
  2. It creates an extra table which increases the memory footprint of your DB indexes

Now, in your first example, both sides are owning the association, and this is bad.

While the @JoinColumn would let the @OneToMany side in charge of the association, it's definitely not the best choice. Therefore, always use the mappedBy attribute on the @OneToMany side.

public class User{
    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL, mappedBy="user")
    public List<APost> aPosts;

    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.ALL, mappedBy="user")
    public List<BPost> bPosts;
}

public class BPost extends Post {

    @ManyToOne(fetch=FetchType.LAZY)    
    public User user;
}

public class APost extends Post {

     @ManyToOne(fetch=FetchType.LAZY) 
     public User user;
}

How to pass a vector to a function?

You're passing in a pointer *random but you're using it like a reference &random

The pointer (what you have) says "This is the address in memory that contains the address of random"

The reference says "This is the address of random"

What Does This Mean in PHP -> or =>

->

calls/sets object variables. Ex:

$obj = new StdClass;
$obj->foo = 'bar';
var_dump($obj);

=> Sets key/value pairs for arrays. Ex:

$array = array(
    'foo' => 'bar'
);
var_dump($array);

How to check if a MySQL query using the legacy API was successful?

This is the first example in the manual page for mysql_query:

$result = mysql_query('SELECT * WHERE 1=1');
if (!$result) {
    die('Invalid query: ' . mysql_error());
}

If you wish to use something other than die, then I'd suggest trigger_error.

How to split a delimited string in Ruby and convert it to an array?

For String Integer without space as String

arr = "12345"

arr.split('')

output: ["1","2","3","4","5"]

For String Integer with space as String

arr = "1 2 3 4 5"

arr.split(' ')

output: ["1","2","3","4","5"]

For String Integer without space as Integer

arr = "12345"

arr.split('').map(&:to_i)

output: [1,2,3,4,5]

For String

arr = "abc"

arr.split('')

output: ["a","b","c"]

Explanation:

  1. arr -> string which you're going to perform any action.
  2. split() -> is an method, which split the input and store it as array.
  3. '' or ' ' or ',' -> is an value, which is needed to be removed from given string.

Why does ANT tell me that JAVA_HOME is wrong when it is not?

I encountered the same problem when I try to run Ant build using the following command:

java -cp ant.jar:ant-launcher.jar org.apache.tools.ant.Main

The output of the command is:

BUILD FAILED
XXX/build.xml:8: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "/usr/lib/jvm/java-6-openjdk/jre"

It seems the java executable is picking "/usr/lib/jvm/java-6-openjdk/jre" as JAVA_HOME, as opposed to "/usr/lib/jvm/java-6-openjdk" where JDK is installed.

I resolved this issue by setting fork="yes" in my <javac> task.

Take a look at: http://ant.apache.org/manual/Tasks/javac.html

How to save data in an android app

There is a lot of options to store your data and Android offers you to chose anyone Your data storage options are the following:

Shared Preferences Store private primitive data in key-value pairs. Internal Storage Store private data on the device memory. External Storage Store public data on the shared external storage. SQLite Databases Store structured data in a private database. Network Connection Store data on the web with your own network server

Check here for examples and tuto

Open Source Javascript PDF viewer

There are some guys at Mozilla working on implementing a PDF reader using HTML5 and JavaScript. It is called pdf.js and one of the developers just made an interesting blog post about the project.

ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)

Open a terminal and take a look at:

/Applications/Python 3.6/Install Certificates.command

Python 3.6 on MacOS uses an embedded version of OpenSSL, which does not use the system certificate store. More details here.

(To be explicit: MacOS users can probably resolve by opening Finder and double clicking Install Certificates.command)

Using ListView : How to add a header view?

I found out that inflating the header view as:

inflater.inflate(R.layout.listheader, container, false);

being container the Fragment's ViewGroup, inflates the headerview with a LayoutParam that extends from FragmentLayout but ListView expect it to be a AbsListView.LayoutParams instead.

So, my problem was solved solved by inflating the header view passing the list as container:

ListView list = fragmentview.findViewById(R.id.listview);
View headerView = inflater.inflate(R.layout.listheader, list, false);

then

list.addHeaderView(headerView, null, false);

Kinda late answer but I hope this can help someone

Code for best fit straight line of a scatter plot in python

Have implemented @Micah 's solution to generate a trendline with a few changes and thought I'd share:

  • Coded as a function
  • Option for a polynomial trendline (input order=2)
  • Function can also just return the coefficient of determination (R^2, input Rval=True)
  • More Numpy array optimisations

Code:

def trendline(xd, yd, order=1, c='r', alpha=1, Rval=False):
    """Make a line of best fit"""

    #Calculate trendline
    coeffs = np.polyfit(xd, yd, order)

    intercept = coeffs[-1]
    slope = coeffs[-2]
    power = coeffs[0] if order == 2 else 0

    minxd = np.min(xd)
    maxxd = np.max(xd)

    xl = np.array([minxd, maxxd])
    yl = power * xl ** 2 + slope * xl + intercept

    #Plot trendline
    plt.plot(xl, yl, c, alpha=alpha)

    #Calculate R Squared
    p = np.poly1d(coeffs)

    ybar = np.sum(yd) / len(yd)
    ssreg = np.sum((p(xd) - ybar) ** 2)
    sstot = np.sum((yd - ybar) ** 2)
    Rsqr = ssreg / sstot

    if not Rval:
        #Plot R^2 value
        plt.text(0.8 * maxxd + 0.2 * minxd, 0.8 * np.max(yd) + 0.2 * np.min(yd),
                 '$R^2 = %0.2f$' % Rsqr)
    else:
        #Return the R^2 value:
        return Rsqr

How do change the color of the text of an <option> within a <select>?

I was recently having trouble with this same thing and I found a really simple solution.

All you have to do is set the first option to disabled and selected. Like this:

_x000D_
_x000D_
<select id="select">_x000D_
    <option disabled="disabled" selected="selected">select one option</option>_x000D_
    <option>one</option>_x000D_
    <option>two</option>_x000D_
    <option>three</option>_x000D_
    <option>four</option>_x000D_
    <option>five</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

This will display the first option (grayed out) when the page is loaded. It also prevents the user from being able to select it once they click on the list.

What is phtml, and when should I use a .phtml extension rather than .php?

To give an example to what Alex said, if you're using Magento, for example, .phtml files are only to be found in the /design area as template files, and contain both HTML and PHP lines. Meanwhile the PHP files are pure code and don't have any lines of HTML in them.

python ValueError: invalid literal for float()

I had a similar issue reading the serial output from a digital scale. I was reading [3:12] out of a 18 characters long output string.

In my case sometimes there is a null character "\x00" (NUL) which magically appears in the scale's reply string and is not printed.

I was getting the error:

> '     0.00'
> 3 0 fast loop, delta =  10.0 weight =  0.0 
> '     0.00'
> 1 800 fast loop, delta = 10.0 weight =  0.0 
> '     0.00'
> 6 0 fast loop, delta =  10.0 weight =  0.0
> '     0\x00.0' 
> Traceback (most recent call last):
>   File "measure_weight_speed.py", line 172, in start
>     valueScale = float(answer_string) 
>     ValueError: invalid literal for float(): 0

After some research I wrote few lines of code that work in my case.

replyScale = scale_port.read(18)
answer = replyScale[3:12]
answer_decode = answer.replace("\x00", "")
answer_strip = str(answer_decode.strip())
print(repr(answer_strip))
valueScale = float(answer_strip)

The answers in these posts helped:

  1. How to get rid of \x00 in my array of bytes?
  2. Invalid literal for float(): 0.000001, how to fix error?

What is the use of the square brackets [] in sql statements?

They are useful to identify each elements in SQL.

For example:

CREATE TABLE SchemaName.TableName (

This would actually create a table by the name SchemaName.TableName under default dbo schema even though the intention might be to create the table inside the SchemaName schema.

The correct way would be the following:

CREATE TABLE [SchemaName].[TableName] (

Now it it knows what is the table name and in which schema should it be created in (rightly in the SchemaName schema and not in the default dbo schema)

How to create a TextArea in Android

Use TextView inside a ScrollView

<ScrollView
    android:id="@+id/ScrollView01"
    android:layout_width="wrap_content"
    android:layout_height="150dip">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</ScrollView>

How to print last two columns using awk

using gawk exhibits the problem:

 gawk '{ print $NF-1, $NF}' filename
1 2
2 3
-1 one
-1 three
# cat filename
1 2
2 3
one
one two three

I just put gawk on Solaris 10 M4000: So, gawk is the cuplrit on the $NF-1 vs. $(NF-1) issue. Next question what does POSIX say? per:

http://www.opengroup.org/onlinepubs/009695399/utilities/awk.html

There is no direction one way or the other. Not good. gawk implies subtraction, other awks imply field number or subtraction. hmm.

Folder structure for a Node.js project

There is a discussion on GitHub because of a question similar to this one: https://gist.github.com/1398757

You can use other projects for guidance, search in GitHub for:

  • ThreeNodes.js - in my opinion, seems to have a specific structure not suitable for every project;
  • lighter - an more simple structure, but lacks a bit of organization;

And finally, in a book (http://shop.oreilly.com/product/0636920025344.do) suggests this structure:

+-- index.html
+-- js/
¦   +-- main.js
¦   +-- models/
¦   +-- views/
¦   +-- collections/
¦   +-- templates/
¦   +-- libs/
¦       +-- backbone/
¦       +-- underscore/
¦       +-- ...
+-- css/
+-- ...

curl: (6) Could not resolve host: google.com; Name or service not known

Issues were:

  1. IPV6 enabled
  2. Wrong DNS server

Here is how I fixed it:

IPV6 Disabling

  • Open Terminal
  • Type su and enter to log in as the super user
  • Enter the root password
  • Type cd /etc/modprobe.d/ to change directory to /etc/modprobe.d/
  • Type vi disableipv6.conf to create a new file there
  • Press Esc + i to insert data to file
  • Type install ipv6 /bin/true on the file to avoid loading IPV6 related modules
  • Type Esc + : and then wq for save and exit
  • Type reboot to restart fedora
  • After reboot open terminal and type lsmod | grep ipv6
  • If no result, it means you properly disabled IPV6

Add Google DNS server

  • Open Terminal
  • Type su and enter to log in as the super user
  • Enter the root password
  • Type cat /etc/resolv.conf to check what DNS server your Fedora using. Mostly this will be your Modem IP address.
  • Now we have to Find a powerful DNS server. Luckily there is a open DNS server maintain by Google.
  • Go to this page and find out what are the "Google Public DNS IP addresses"
  • Today those are 8.8.8.8 and 8.8.4.4. But in future those may change.
  • Type vi /etc/resolv.conf to edit the resolv.conf file
  • Press Esc + i for insert data to file
  • Comment all the things in the file by inserting # at the begin of the each line. Do not delete anything because can be useful in future.
  • Type below two lines in the file

    nameserver 8.8.8.8
    nameserver 8.8.4.4

    -Type Esc + : and then wq for save and exit

  • Now you are done and everything works fine (Not necessary to restart).
  • But every time when you restart the computer your /etc/resolv.conf will be replaced by default. So I'll let you find a way to avoid that.

Here is my blog post about this: http://codeketchup.blogspot.sg/2014/07/how-to-fix-curl-6-could-not-resolve.html

How to initialize a nested struct?

Define your Proxy struct separately, outside of Configuration, like this:

type Proxy struct {
    Address string
    Port    string
}

type Configuration struct {
    Val string
    P   Proxy
}

c := &Configuration{
    Val: "test",
    P: Proxy{
        Address: "addr",
        Port:    "80",
    },
}

See http://play.golang.org/p/7PELCVsQIc

How do I delete virtual interface in Linux?

Have you tried:

ifconfig 10:35978f0 down

As the physical interface is 10 and the virtual aspect is after the colon :.

See also https://www.cyberciti.biz/faq/linux-command-to-remove-virtual-interfaces-or-network-aliases/

How do I set the value property in AngularJS' ng-options?

For me the answer by Bruno Gomes is the best answer.

But actually, you need not worry about setting the value property of select options. AngularJS will take care of that. Let me explain in detail.

Please consider this fiddle

angular.module('mySettings', []).controller('appSettingsCtrl', function ($scope) {

    $scope.timeFormatTemplates = [{
        label: "Seconds",
        value: 'ss'
    }, {
        label: "Minutes",
        value: 'mm'
    }, {
        label: "Hours",
        value: 'hh'
    }];


    $scope.inactivity_settings = {
        status: false,
        inactive_time: 60 * 5 * 3, // 15 min (default value), that is, 900 seconds
        //time_format: 'ss', // Second (default value)
        time_format: $scope.timeFormatTemplates[0], // Default seconds object
    };

    $scope.activity_settings = {
        status: false,
        active_time: 60 * 5 * 3, // 15 min (default value), that is,  900 seconds
        //time_format: 'ss', // Second (default value)
        time_format: $scope.timeFormatTemplates[0], // Default seconds object
    };

    $scope.changedTimeFormat = function (time_format) {
        'use strict';

        console.log('time changed');
        console.log(time_format);
        var newValue = time_format.value;

        // do your update settings stuffs
    }
});

As you can see in the fiddle output, whatever you choose for select box options, it is your custom value, or the 0, 1, 2 auto generated value by AngularJS, it does not matter in your output unless you are using jQuery or any other library to access the value of that select combo box options and manipulate it accordingly.

How to set text size of textview dynamically for different screens

EDIT: And As I Search on StackOverflow now I found This Question is Duplicate of : This and This

You need to use another function setTextSize(unit, size) with unit SP like this,

tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18f);

Please read more for TypedValue constants.

Improve subplot size/spacing with many subplots in matplotlib

You can use plt.subplots_adjust to change the spacing between the subplots (source)

call signature:

subplots_adjust(left=None, bottom=None, right=None, top=None, wspace=None, hspace=None)

The parameter meanings (and suggested defaults) are:

left  = 0.125  # the left side of the subplots of the figure
right = 0.9    # the right side of the subplots of the figure
bottom = 0.1   # the bottom of the subplots of the figure
top = 0.9      # the top of the subplots of the figure
wspace = 0.2   # the amount of width reserved for blank space between subplots
hspace = 0.2   # the amount of height reserved for white space between subplots

The actual defaults are controlled by the rc file

String parsing in Java with delimiter tab "\t" using split

String.split implementations will have serious limitations if the data in a tab-delimited field itself contains newline, tab and possibly " characters.

TAB-delimited formats have been around for donkey's years, but format is not standardised and varies. Many implementations don't escape characters (newlines and tabs) appearing within a field. Rather, they follow CSV conventions and wrap any non-trivial fields in "double quotes". Then they escape only double-quotes. So a "line" could extend over multiple lines.

Reading around I heard "just reuse apache tools", which sounds like good advice.

In the end I personally chose opencsv. I found it light-weight, and since it provides options for escape and quote characters it should cover most popular comma- and tab- delimited data formats.

Example:

CSVReader tabFormatReader = new CSVReader(new FileReader("yourfile.tsv"), '\t');

Remove or adapt border of frame of legend using matplotlib

One more related question, since it took me forever to find the answer:

How to make the legend background blank (i.e. transparent, not white):

legend = plt.legend()
legend.get_frame().set_facecolor('none')

Warning, you want 'none' (the string). None means the default color instead.

syntaxerror: unexpected character after line continuation character in python

You need to quote that filename:

f = open("D\\python\\HW\\2_1 - Copy.cp", "r")

Otherwise the bare backslash after the D is interpreted as a line-continuation character, and should be followed by a newline. This is used to extend long expressions over multiple lines, for readability:

print "This is a long",\
      "line of text",\
      "that I'm printing."

Also, you shouldn't have semicolons (;) at the end of your statements in Python.

How to use onClick with divs in React.js

This also works:

I just changed with this.state.color==='white'?'black':'white'.

You can also pick the color from drop-down values and update in place of 'black';

(CodePen)

What does "subject" mean in certificate?

My typical expectation is than when "subject" is used a context like this, it means the target of the certificate. If you think of a certificate as a cryptographically secured description of a thing (person, device, communication channel, etc), then the subject is the stuff related to that thing.

It's not the thing itself. For example, no one would say "the subject takes his SmartCard and authenticates his PIN". That would be the "user".

But it usually relates to the various data items related to that that thing. For example:

  • Subject DN = Subject Distinguished Name = the unique identifier for what this thing is. Includes information about the thing being certified, including common name, organization, organization unit, country codes, etc.
  • Subject Key = part (or all) of the certificate's private/public key pair. If it's coming from the certificate, it's the public key. If it's coming from a key store in a secure location, it's probably the private key. Either part of the key is the cryptographic data used by the thing that received the certificate.
  • Subject certificate - the end point for the transaction - this is the thing requesting some secure capability - like integrity checking, authentication, privacy, etc.

Usually, it's used to distinguish between the other players in the PKI world. Namely the "issuer" and the "root". The issuer is the CA that issued the cert (to the subject), and the root is the CA that is end point of all the trust in the heirarchy. The typical relationship is root--->issuer--->subject.

How to get controls in WPF to fill available space?

There are also some properties you can set to force a control to fill its available space when it would otherwise not do so. For example, you can say:

HorizontalContentAlignment="Stretch"

... to force the contents of a control to stretch horizontally. Or you can say:

HorizontalAlignment="Stretch"

... to force the control itself to stretch horizontally to fill its parent.

How to get DateTime.Now() in YYYY-MM-DDThh:mm:ssTZD format using C#

Try this:

DateTime.Now.ToString("yyyy-MM-ddThh:mm:sszzz");

zzz is the timezone offset.

Python: Binary To Decimal Conversion

You can use int casting which allows the base specification.

int(b, 2)  # Convert a binary string to a decimal int.

Unknown SSL protocol error in connection

execute

nc -v -z <git-repository> <port>

your out put should look like

"Connection to <git-repository> <port> port [tcp/*] succeeded!"

if you get

connect to <git-repository> <port> (tcp) failed: Connection timed out

You need to edit your ~/.ssh/config file. Add something like the following:

Host example.com
Port 1234

How to center a View inside of an Android Layout?

Use ConstraintLayout. Here is an example that will center the view according to the width and height of the parent screen:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="#FF00FF"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHeight_percent=".6"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintWidth_percent=".4"></LinearLayout>
</android.support.constraint.ConstraintLayout>

You might need to change your gradle to get the latest version of ConstraintLayout:

dependencies {
...
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
}

enter image description here

How to retrieve checkboxes values in jQuery

$(document).ready(function() {
  $(':checkbox').click(function() {
    var cObj = $(this);
    var cVal = cObj.val();
    var tObj = $('#t');
    var tVal = tObj.val();
    if (cObj.attr("checked")) {
      tVal = tVal + "," + cVal;
      $('#t').attr("value", tVal);
    } else {
      //TODO remove unchecked value.
    }
  });
});

How to make picturebox transparent?

One fast solution is set image property for image1 and set backgroundimage property to imag2, the only inconvenience is that you have the two images inside the picture box, but you can change background properties to tile, streched, etc. Make sure that backcolor be transparent. Hope this helps

How to use awk sort by column 3

To exclude the first line (header) from sorting, I split it out into two buffers.

df | awk 'BEGIN{header=""; $body=""} { if(NR==1){header=$0}else{body=body"\n"$0}} END{print header; print body|"sort -nk3"}'

Adding a caption to an equation in LaTeX

You may want to look at http://tug.ctan.org/tex-archive/macros/latex/contrib/float/ which allows you to define new floats using \newfloat

I say this because captions are usually applied to floats.

Straight ahead equations (those written with $ ... $, $$ ... $$, begin{equation}...) are in-line objects that do not support \caption.

This can be done using the following snippet just before \begin{document}

\usepackage{float}
\usepackage{aliascnt}
\newaliascnt{eqfloat}{equation}
\newfloat{eqfloat}{h}{eqflts}
\floatname{eqfloat}{Equation}

\newcommand*{\ORGeqfloat}{}
\let\ORGeqfloat\eqfloat
\def\eqfloat{%
  \let\ORIGINALcaption\caption
  \def\caption{%
    \addtocounter{equation}{-1}%
    \ORIGINALcaption
  }%
  \ORGeqfloat
}

and when adding an equation use something like

\begin{eqfloat}
\begin{equation}
f( x ) = ax + b
\label{eq:linear}
\end{equation}
\caption{Caption goes here}
\end{eqfloat}

How to list all Git tags?

Also git show-ref is rather useful, so that you can directly associate tags with correspondent commits:

$ git tag
osgeolive-6.5
v8.0
...

$ git show-ref --tags
e7e66977c1f34be5627a268adb4b9b3d59700e40 refs/tags/osgeolive-6.5
8f27e65bddd7d4b8515ce620fb485fdd78fcdf89 refs/tags/v8.0
...

How do I compare two strings in Perl?

The obvious subtext of this question is:

why can't you just use == to check if two strings are the same?

Perl doesn't have distinct data types for text vs. numbers. They are both represented by the type "scalar". Put another way, strings are numbers if you use them as such.

if ( 4 == "4" ) { print "true"; } else { print "false"; }
true

if ( "4" == "4.0" ) { print "true"; } else { print "false"; }
true

print "3"+4
7

Since text and numbers aren't differentiated by the language, we can't simply overload the == operator to do the right thing for both cases. Therefore, Perl provides eq to compare values as text:

if ( "4" eq "4.0" ) { print "true"; } else { print "false"; }
false

if ( "4.0" eq "4.0" ) { print "true"; } else { print "false"; }
true

In short:

  • Perl doesn't have a data-type exclusively for text strings
  • use == or !=, to compare two operands as numbers
  • use eq or ne, to compare two operands as text

There are many other functions and operators that can be used to compare scalar values, but knowing the distinction between these two forms is an important first step.

How to add screenshot to READMEs in github repository?

I googled a few similar questions and did not see any answers with my problem and its quite simple/easy solution.

Google Cloud Storage - a slightly different approach to images in READMEs

Here goes: like the OP, I wanted an image in my Github README, and, knowing the Markdown syntax for doing so, typed it in:

![My Image](https://storage.cloud.google.com/${MY_BUCKET}/${MY_IMAGE}

You need to complete the actual substitutions above (e.g. MY_IMAGE=image.jpg) for this to work.

But, wait...failure--there's no actual rendered photo! And the link is exactly as given by Google Storage!

screenshot of failed Github image upload

Github camo - Anonymous Images

Github hosts your images anonymously, yay! However, this presents an issue for Google storage assets. You need to get the generated url from your Google Cloud Console.

I'm sure there's a smoother way, however, simply visit your given URL endpoint and copy the long URL. Details:

Instructions

  1. Visit your storage console: https://console.cloud.google.com/storage/browser/${MY_BUCKET}?project=${MY_PROJECT}
  2. Click on the image you'd like to display in Github (this brings up the "Object Details" page)
  3. Copy pasta that URL (the one starting with https not gs) into a new browser tab/window
  4. Copy pasta the new generated URL -- it should be longer -- from your new browser tab/window into your Github README file

Hopefully this helps speed up and clarify this issue for anyone else.

Why can't I initialize non-const static member or static array in class?

I think it's to prevent you from mixing declarations and definitions. (Think about the problems that could occur if you include the file in multiple places.)

How to highlight text using javascript

function stylizeHighlightedString() {

    var text = window.getSelection();

    // For diagnostics
    var start = text.anchorOffset;
    var end = text.focusOffset - text.anchorOffset;

    range = window.getSelection().getRangeAt(0);

    var selectionContents = range.extractContents();
    var span = document.createElement("span");

    span.appendChild(selectionContents);

    span.style.backgroundColor = "yellow";
    span.style.color = "black";

    range.insertNode(span);
}

Enabling CORS in Cloud Functions for Firebase

No CORS solutions worked for me... till now!

Not sure if anyone else ran into the same issue I did, but I set up CORS like 5 different ways from examples I found and nothing seemed to work. I set up a minimal example with Plunker to see if it was really a bug, but the example ran beautifully. I decided to check the firebase functions logs (found in the firebase console) to see if that could tell me anything. I had a couple errors in my node server code, not CORS related, that when I debugged released me of my CORS error message. I don't know why code errors unrelated to CORS returns a CORS error response, but it led me down the wrong rabbit hole for a good number of hours...

tl;dr - check your firebase function logs if no CORS solutions work and debug any errros you have

Could not load NIB in bundle

DO NOT PUT .xib WHEN YOU INSERT IN THE XIB NAME! IT IS ALREADY IMPLIED!

Dont do this:

 UIView *viewFromNib = [[NSBundle mainBundle] loadNibNamed:@"ResultsAssessmentView.xib" owner:self options:nil][0];

Do this:

 UIView *viewFromNib = [[NSBundle mainBundle] loadNibNamed:@"ResultsAssessmentView" owner:self options:nil][0];

Horizontal scroll css?

Below worked for me.

Height & width are taken to show that, if you 2 such children, it will scroll horizontally, since height of child is greater than height of parent scroll vertically.

Parent CSS:

.divParentClass {
    width: 200px;
    height: 100px;
    overflow: scroll;
    white-space: nowrap;
}

Children CSS:

.divChildClass {
    width: 110px;
    height: 200px;
    display: inline-block;
}

To scroll horizontally only:

overflow-x: scroll;
overflow-y: hidden;

To scroll vertically only:

overflow-x: hidden;
overflow-y: scroll;

What is the difference between dynamic and static polymorphism in Java?

  • Method overloading would be an example of static polymorphism

  • whereas overriding would be an example of dynamic polymorphism.

    Because, in case of overloading, at compile time the compiler knows which method to link to the call. However, it is determined at runtime for dynamic polymorphism

http://localhost/ not working on Windows 7. What's the problem?

Uncommenting the following line in host file worked for me,

#127.0.0.1 localhost

What do the python file extensions, .pyc .pyd .pyo stand for?

  • .py - Regular script
  • .py3 - (rarely used) Python3 script. Python3 scripts usually end with ".py" not ".py3", but I have seen that a few times
  • .pyc - compiled script (Bytecode)
  • .pyo - optimized pyc file (As of Python3.5, Python will only use pyc rather than pyo and pyc)
  • .pyw - Python script to run in Windowed mode, without a console; executed with pythonw.exe
  • .pyx - Cython src to be converted to C/C++
  • .pyd - Python script made as a Windows DLL
  • .pxd - Cython script which is equivalent to a C/C++ header
  • .pxi - MyPy stub
  • .pyi - Stub file (PEP 484)
  • .pyz - Python script archive (PEP 441); this is a script containing compressed Python scripts (ZIP) in binary form after the standard Python script header
  • .pywz - Python script archive for MS-Windows (PEP 441); this is a script containing compressed Python scripts (ZIP) in binary form after the standard Python script header
  • .py[cod] - wildcard notation in ".gitignore" that means the file may be ".pyc", ".pyo", or ".pyd".
  • .pth - a path configuration file; its contents are additional items (one per line) to be added to sys.path. See site module.

A larger list of additional Python file-extensions (mostly rare and unofficial) can be found at http://dcjtech.info/topic/python-file-extensions/

Script to Change Row Color when a cell changes text

I used GENEGC's script, but I found it quite slow.

It is slow because it scans whole sheet on every edit.

So I wrote way faster and cleaner method for myself and I wanted to share it.

function onEdit(e) {
    if (e) { 
        var ss = e.source.getActiveSheet();
        var r = e.source.getActiveRange(); 

        // If you want to be specific
        // do not work in first row
        // do not work in other sheets except "MySheet"
        if (r.getRow() != 1 && ss.getName() == "MySheet") {

            // E.g. status column is 2nd (B)
            status = ss.getRange(r.getRow(), 2).getValue();

            // Specify the range with which You want to highlight
            // with some reading of API you can easily modify the range selection properties
            // (e.g. to automatically select all columns)
            rowRange = ss.getRange(r.getRow(),1,1,19);

            // This changes font color
            if (status == 'YES') {
                rowRange.setFontColor("#999999");
            } else if (status == 'N/A') {
                rowRange.setFontColor("#999999");
            // DEFAULT
            } else if (status == '') { 
                rowRange.setFontColor("#000000");
            }   
        }
    }
}

Indent multiple lines quickly in vi

Suppose | represents the position of the cursor in Vim. If the text to be indented is enclosed in a code block like:

int main() {
line1
line2|
line3
}

you can do >i{ which means "indent (>) inside (i) block ({)" and get:

int main() {
    line1
    line2|
    line3
}

Now suppose the lines are contiguous but outside a block, like:

do
line2|
line3
line4
done

To indent lines 2 thru 4 you can visually select the lines and type >. Or even faster you can do >2j to get:

do
    line2|
    line3
    line4
done

Note that >Nj means indent from current line to N lines below. If the number of lines to be indented is large, it could take some seconds for the user to count the proper value of N. To save valuable seconds you can activate the option of relative number with set relativenumber (available since Vim version 7.3).

Get type of a generic parameter in Java with reflection

As pointed out by @bertolami, it's not possible to us a variable type and get its future value (the content of typeOfList variable).

Nevertheless, you can pass the class as parameter on it like this:

public final class voodoo {
    public static void chill(List<T> aListWithTypeSpiderMan, Class<T> clazz) {
        // Here I'd like to get the Class-Object 'SpiderMan'
        Class typeOfTheList = clazz;
    }

    public static void main(String... args) {
        chill(new List<SpiderMan>(), Spiderman.class );
    }
}

That's more or less what Google does when you have to pass a class variable to the constructor of ActivityInstrumentationTestCase2.

How to load data from a text file in a PostgreSQL database?

Let consider that your data are in the file values.txt and that you want to import them in the database table myTable then the following query does the job

COPY myTable FROM 'value.txt' (DELIMITER('|'));

https://www.postgresql.org/docs/current/static/sql-copy.html

Bootstrap Modal immediately disappearing

I too had the issue, if the button is inside a tag then the modal appears once and disappears soon enough, taking the button out of the form fixed the isue. Thanks I ended up in this thread! +1 to all.

LEFT function in Oracle

I've discovered that LEFT and RIGHT are not supported functions in Oracle. They are used in SQL Server, MySQL, and some other versions of SQL. In Oracle, you need to use the SUBSTR function. Here are simple examples:

LEFT ('Data', 2) = 'Da'

->   SUBSTR('Data',1,2) = 'Da'

RIGHT ('Data', 2) = 'ta'

->   SUBSTR('Data',-2,2) = 'ta'

Notice that a negative number counts back from the end.

how to convert a string date into datetime format in python?

The particular format for strptime:

datetime.datetime.strptime(string_date, "%Y-%m-%d %H:%M:%S.%f")
#>>> datetime.datetime(2013, 9, 28, 20, 30, 55, 782000)

Fixing broken UTF-8 encoding

This script had a nice approach. Converting it to the language of your choice should not be too difficult:

http://plasmasturm.org/log/416/

#!/usr/bin/perl
use strict;
use warnings;

use Encode qw( decode FB_QUIET );

binmode STDIN, ':bytes';
binmode STDOUT, ':encoding(UTF-8)';

my $out;

while ( <> ) {
  $out = '';
  while ( length ) {
    # consume input string up to the first UTF-8 decode error
    $out .= decode( "utf-8", $_, FB_QUIET );
    # consume one character; all octets are valid Latin-1
    $out .= decode( "iso-8859-1", substr( $_, 0, 1 ), FB_QUIET ) if length;
  }
  print $out;
}

Can I make dynamic styles in React Native?

Here is what worked for me:

render() {
  const { styleValue } = this.props;
  const dynamicStyleUpdatedFromProps = {
    height: styleValue,
    width: styleValue,
    borderRadius: styleValue,
  }

  return (
    <View style={{ ...styles.staticStyleCreatedFromStyleSheet, ...dynamicStyleUpdatedFromProps }} />
  );
}

For some reason, this was the only way that mine would update properly.

xpath find if node exists

A variation when using xpath in Java using count():

int numberofbodies = Integer.parseInt((String) xPath.evaluate("count(/html/body)", doc));
if( numberofbodies==0) {
    // body node missing
}

Refresh an asp.net page on button click

Page reload can be done using javascript code. Use either a HTML button and implement it like...

<input type="button" value="Reload Page" onClick="document.location.reload(true)">

Detect the Internet connection is offline?

The HTML5 Application Cache API specifies navigator.onLine, which is currently available in the IE8 betas, WebKit (eg. Safari) nightlies, and is already supported in Firefox 3

Text-align class for inside a table

No, Bootstrap doesn't have a class for that, but this kind of class is considered a "utility" class, similar to the ".pull-right" class that @anton mentioned.

If you look at utilities.less you will see very few utility classes in Bootstrap, the reason being that this kind of class is generally frowned upon, and is recommended to be used for either: a) prototyping and development - so you can quickly build out your pages, then remove the pull-right and pull-left classes in favor of applying floats to more semantic classes or to the elements themselves, or b) when it's clearly more practical than a more semantic solution.

In your case, by your question it looks like you wish to have certain text align on the right in your table, but not all of it. Semantically, it would be better to do something like (I'm just going to make up a few classes here, except for the default bootstrap class, .table):

  <table class="table price-table">
    <thead>
      <th class="price-label">Total</th>
    </thead>
    <tbody>
      <tr>
        <td class="price-value">$1,000,000.00</td>
      </tr>
    </tbody>
  </table>

And just apply the text-align: left or text-align: right declarations to the price-value and price-label classes (or whatever classes work for you).

The problem with applying align-right as a class, is that if you want to refactor your tables you will have to redo the markup and the styles. If you use semantic classes you might be able to get away with refactoring only the CSS content. Plus, if are taking the time to apply a class to an element, it's best practice to try to assign semantic value to that class so that the markup is easier to navigate for other programmers (or you three months later).

One way to think of it is this: when you pose the question "What is this td for?", you will not get clarification from the answer "align-right".

Finding duplicate values in MySQL

I improved from this:

SELECT 
    col, 
    COUNT(col)
FROM
    table_name
GROUP BY col
HAVING COUNT(col) > 1; 

How can I make this try_files directive work?

a very common try_files line which can be applied on your condition is

location / {
    try_files $uri $uri/ /test/index.html;
}

you probably understand the first part, location / matches all locations, unless it's matched by a more specific location, like location /test for example

The second part ( the try_files ) means when you receive a URI that's matched by this block try $uri first, for example http://example.com/images/image.jpg nginx will try to check if there's a file inside /images called image.jpg if found it will serve it first.

Second condition is $uri/ which means if you didn't find the first condition $uri try the URI as a directory, for example http://example.com/images/, ngixn will first check if a file called images exists then it wont find it, then goes to second check $uri/ and see if there's a directory called images exists then it will try serving it.

Side note: if you don't have autoindex on you'll probably get a 403 forbidden error, because directory listing is forbidden by default.

EDIT: I forgot to mention that if you have index defined, nginx will try to check if the index exists inside this folder before trying directory listing.

Third condition /test/index.html is considered a fall back option, (you need to use at least 2 options, one and a fall back), you can use as much as you can (never read of a constriction before), nginx will look for the file index.html inside the folder test and serve it if it exists.

If the third condition fails too, then nginx will serve the 404 error page.

Also there's something called named locations, like this

location @error {
}

You can call it with try_files like this

try_files $uri $uri/ @error;

TIP: If you only have 1 condition you want to serve, like for example inside folder images you only want to either serve the image or go to 404 error, you can write a line like this

location /images {
    try_files $uri =404;
}

which means either serve the file or serve a 404 error, you can't use only $uri by it self without =404 because you need to have a fallback option.
You can also choose which ever error code you want, like for example:

location /images {
    try_files $uri =403;
}

This will show a forbidden error if the image doesn't exist, or if you use 500 it will show server error, etc ..

Simpler way to check if variable is not equal to multiple string values?

If you're planning on building a function in the if statement, I'd also advise the use of in_array. It's a lot cleaner.

If you're attempting to assign values to variables you can use the if/else shorthand:

$variable_to_fill = $some_variable !== 'uk' ? false : true;

How to replace all occurrences of a string in Javascript?

Starting from v85, chrome now supports String.prototype.replaceAll natively. Note this outperform all other proposed solutions and should be used once majorly supported.

Feature status: https://chromestatus.com/feature/6040389083463680

_x000D_
_x000D_
var s = "hello hello world";
s = s.replaceAll("hello", ""); // s is now "world"
console.log(s)
_x000D_
_x000D_
_x000D_

Is there a way to make npm install (the command) to work behind proxy?

Just open the new terminal and type npm config edit and npm config -g edit. Reset to defaults. After that close terminal, open the new one and type npm --without-ssl --insecure --proxy http://username:password@proxy:8080 install <package> if you need globally just add -g.

It worked for me, hope it`ll work for you :)

Reading a huge .csv file

what worked for me was and is superfast is

import pandas as pd
import dask.dataframe as dd
import time
t=time.clock()
df_train = dd.read_csv('../data/train.csv', usecols=[col1, col2])
df_train=df_train.compute()
print("load train: " , time.clock()-t)

Another working solution is:

import pandas as pd 
from tqdm import tqdm

PATH = '../data/train.csv'
chunksize = 500000 
traintypes = {
'col1':'category',
'col2':'str'}

cols = list(traintypes.keys())

df_list = [] # list to hold the batch dataframe

for df_chunk in tqdm(pd.read_csv(PATH, usecols=cols, dtype=traintypes, chunksize=chunksize)):
    # Can process each chunk of dataframe here
    # clean_data(), feature_engineer(),fit()

    # Alternatively, append the chunk to list and merge all
    df_list.append(df_chunk) 

# Merge all dataframes into one dataframe
X = pd.concat(df_list)

# Delete the dataframe list to release memory
del df_list
del df_chunk

Python 3.2 Unable to import urllib2 (ImportError: No module named urllib2)

In python 3 urllib2 was merged into urllib. See also another Stack Overflow question and the urllib PEP 3108.

To make Python 2 code work in Python 3:

try:
    import urllib.request as urllib2
except ImportError:
    import urllib2

How to parse a String containing XML in Java and retrieve the value of the root node?

Using JDOM:

String xml = "<message>HELLO!</message>";
org.jdom.input.SAXBuilder saxBuilder = new SAXBuilder();
try {
    org.jdom.Document doc = saxBuilder.build(new StringReader(xml));
    String message = doc.getRootElement().getText();
    System.out.println(message);
} catch (JDOMException e) {
    // handle JDOMException
} catch (IOException e) {
    // handle IOException
}

Using the Xerces DOMParser:

String xml = "<message>HELLO!</message>";
DOMParser parser = new DOMParser();
try {
    parser.parse(new InputSource(new java.io.StringReader(xml)));
    Document doc = parser.getDocument();
    String message = doc.getDocumentElement().getTextContent();
    System.out.println(message);
} catch (SAXException e) {
    // handle SAXException 
} catch (IOException e) {
    // handle IOException 
}

Using the JAXP interfaces:

String xml = "<message>HELLO!</message>";
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = null;
try {
    db = dbf.newDocumentBuilder();
    InputSource is = new InputSource();
    is.setCharacterStream(new StringReader(xml));
    try {
        Document doc = db.parse(is);
        String message = doc.getDocumentElement().getTextContent();
        System.out.println(message);
    } catch (SAXException e) {
        // handle SAXException
    } catch (IOException e) {
        // handle IOException
    }
} catch (ParserConfigurationException e1) {
    // handle ParserConfigurationException
}

PYODBC--Data source name not found and no default driver specified

Have you installed any product of SQL in your system machine ? You can download and install "ODBC Driver 13(or any version) for SQL Server" and try to run if you havent alerady done.

Iterating through a List Object in JSP

you can read empList directly in forEach tag.Try this

 <table>
       <c:forEach items="${sessionScope.empList}" var="employee">
            <tr>
                <td>Employee ID: <c:out value="${employee.eid}"/></td>
                <td>Employee Pass: <c:out value="${employee.ename}"/></td>  
            </tr>
        </c:forEach>
    </table>

docker command not found even though installed with apt-get

IMPORTANT - on ubuntu package docker is something entirely different ( avoid it ) :

issue following to view what if any packages you have mentioning docker

dpkg -l|grep docker

if only match is following then you do NOT have docker installed below is an unrelated package

docker - System tray for KDE3/GNOME2 docklet applications

if you see something similar to following then you have docker installed

 dpkg -l|grep docker

ii  docker-ce                                  5:19.03.13~3-0~ubuntu-focal         amd64        Docker: the open-source application container engine
ii  docker-ce-cli                              5:19.03.13~3-0~ubuntu-focal         amd64        Docker CLI: the open-source application container engine

NOTE - ubuntu package docker.io is not getting updates ( obsolete do NOT use )


Instead do this : install the latest version of docker on linux by executing the following:

  sudo curl -sSL https://get.docker.com/ | sh
# sudo curl -sSL https://test.docker.com | sh  # get dev pipeline version
  

here is a typical output ( ubuntu 16.04 )

apparmor is enabled in the kernel and apparmor utils were already installed
+ sudo -E sh -c apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
Executing: /tmp/tmp.rAAGu0P85R/gpg.1.sh --keyserver
hkp://ha.pool.sks-keyservers.net:80
--recv-keys
58118E89F3A912897C070ADBF76221572C52609D
gpg: requesting key 2C52609D from hkp server ha.pool.sks-keyservers.net
gpg: key 2C52609D: "Docker Release Tool (releasedocker) <[email protected]>" 1 new signature
gpg: Total number processed: 1
gpg:         new signatures: 1
+ break
+ sudo -E sh -c apt-key adv -k 58118E89F3A912897C070ADBF76221572C52609D >/dev/null
+ sudo -E sh -c mkdir -p /etc/apt/sources.list.d
+ dpkg --print-architecture
+ sudo -E sh -c echo deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main > /etc/apt/sources.list.d/docker.list
+ sudo -E sh -c sleep 3; apt-get update; apt-get install -y -q docker-engine
Hit:1 http://repo.steampowered.com/steam precise InRelease
Hit:2 http://download.virtualbox.org/virtualbox/debian xenial InRelease                                                           
Ign:3 http://dl.google.com/linux/chrome/deb stable InRelease                                                                      
Hit:4 http://dl.google.com/linux/chrome/deb stable Release                                                                        
Hit:5 http://archive.canonical.com/ubuntu xenial InRelease                                                                        
Hit:6 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial InRelease                                                     
Hit:7 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-updates InRelease                                             
Hit:8 http://ppa.launchpad.net/me-davidsansome/clementine/ubuntu xenial InRelease                                                 
Ign:9 http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.2 InRelease                                                         
Hit:10 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-backports InRelease                                          
Hit:11 http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.2 Release                                                          
Hit:12 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial-security InRelease                                           
Hit:14 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease                                                                 
Ign:15 http://linux.dropbox.com/ubuntu wily InRelease                                                                             
Ign:16 http://repo.vivaldi.com/stable/deb stable InRelease                                                                        
Hit:17 http://repo.vivaldi.com/stable/deb stable Release                                                                          
Get:18 http://linux.dropbox.com/ubuntu wily Release [6,596 B]            
Get:19 https://apt.dockerproject.org/repo ubuntu-xenial InRelease [20.6 kB]    
Ign:20 http://packages.amplify.nginx.com/ubuntu xenial InRelease                      
Hit:22 http://packages.amplify.nginx.com/ubuntu xenial Release
Hit:23 https://deb.opera.com/opera-beta stable InRelease
Hit:26 https://deb.opera.com/opera-developer stable InRelease
Get:28 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 Packages [1,719 B]
Hit:29 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
Fetched 28.9 kB in 1s (17.2 kB/s)
Reading package lists... Done
W: http://repo.mongodb.org/apt/debian/dists/wheezy/mongodb-org/3.2/Release.gpg: Signature by key 42F3E95A2C4F08279C4960ADD68FA50FEA312927 uses weak digest algorithm (SHA1)
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  aufs-tools cgroupfs-mount
The following NEW packages will be installed:
  aufs-tools cgroupfs-mount docker-engine
0 upgraded, 3 newly installed, 0 to remove and 17 not upgraded.
Need to get 14.6 MB of archives.
After this operation, 73.7 MB of additional disk space will be used.
Get:1 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial/universe amd64 aufs-tools amd64 1:3.2+20130722-1.1ubuntu1 [92.9 kB]
Get:2 http://mirror.cc.columbia.edu/pub/linux/ubuntu/archive xenial/universe amd64 cgroupfs-mount all 1.2 [4,970 B]
Get:3 https://apt.dockerproject.org/repo ubuntu-xenial/main amd64 docker-engine amd64 1.11.2-0~xenial [14.5 MB]
Fetched 14.6 MB in 7s (2,047 kB/s)
Selecting previously unselected package aufs-tools.
(Reading database ... 427978 files and directories currently installed.)
Preparing to unpack .../aufs-tools_1%3a3.2+20130722-1.1ubuntu1_amd64.deb ...
Unpacking aufs-tools (1:3.2+20130722-1.1ubuntu1) ...
Selecting previously unselected package cgroupfs-mount.
Preparing to unpack .../cgroupfs-mount_1.2_all.deb ...
Unpacking cgroupfs-mount (1.2) ...
Selecting previously unselected package docker-engine.
Preparing to unpack .../docker-engine_1.11.2-0~xenial_amd64.deb ...
Unpacking docker-engine (1.11.2-0~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu6) ...
Setting up aufs-tools (1:3.2+20130722-1.1ubuntu1) ...
Setting up cgroupfs-mount (1.2) ...
Setting up docker-engine (1.11.2-0~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu3) ...
Processing triggers for systemd (229-4ubuntu6) ...
Processing triggers for ureadahead (0.100.0-19) ...
+ sudo -E sh -c docker version
Client:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 22:00:43 2016
 OS/Arch:      linux/amd64

Server:
 Version:      1.11.2
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   b9f10c9
 Built:        Wed Jun  1 22:00:43 2016
 OS/Arch:      linux/amd64

If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:

  sudo usermod -aG docker stens

Remember that you will have to log out and back in for this to take effect!

Here is the underlying detailed install instructions which as you can see comes bundled into above technique ... Above one liner gives you same as :

https://docs.docker.com/engine/installation/linux/ubuntulinux/

Once installed you can see what docker packages were installed by issuing

dpkg -l|grep docker
ii  docker-ce                                  5:19.03.13~3-0~ubuntu-focal         amd64        Docker: the open-source application container engine
ii  docker-ce-cli                              5:19.03.13~3-0~ubuntu-focal         amd64        Docker CLI: the open-source application container engine

now Docker updates will get installed going forward when you issue

sudo apt-get update
sudo apt-get upgrade

take a look at

 ls -latr /etc/apt/sources.list.d/*docker*
-rw-r--r-- 1 root root 202 Jun 23 10:01 /etc/apt/sources.list.d/docker.list.save
-rw-r--r-- 1 root root  71 Jul  4 11:32 /etc/apt/sources.list.d/docker.list


cat /etc/apt/sources.list.d/docker.list

deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main

or more generally

cd /etc/apt
grep -r docker *
sources.list.d/docker.list:deb [arch=amd64] https://download.docker.com/linux/ubuntu focal test

How do I invoke a Java method when given the method name as a string?

I do this like this:

try {
    YourClass yourClass = new YourClass();
    Method method = YourClass.class.getMethod("yourMethodName", ParameterOfThisMethod.class);
    method.invoke(yourClass, parameter);
} catch (Exception e) {
    e.printStackTrace();
}

Git fails when pushing commit to github

The Problem to push mostly is because of the size of the files that need to be pushed. I was trying to push some libraries of just size 2 mb, then too the push was giving error of RPC with result 7. The line is of 4 mbps and is working fine. Some subsequent tries to the push got me success. If such error comes, wait for few minutes and keep on trying.

I also found out that there are some RPC failures if the github is down or is getting unstable network at their side.

So keeping up trying after some intervals is the only option!

How can I set a DateTimePicker control to a specific date?

If you want to set a date, DateTimePicker.Value is a DateTime object.

DateTimePicker.Value = new DateTime(2012,05,28);

This is the constructor of DateTime:

new DateTime(int year,int month,int date);

My Visual is 2012

SQL select join: is it possible to prefix all columns as 'prefix.*'?

In postgres, I use the json functions to instead return json objects.... then, after querying, I json_decode the fields with a _json suffix.

IE:

select row_to_json(tab1.*),tab1_json, row_to_json(tab2.*) tab2_json 
 from tab1
 join tab2 on tab2.t1id=tab1.id

then in PHP (or any other language), I loop through the returned columns and json_decode() them if they have the "_json" suffix (also removing the suffix. In the end, I get an object called "tab1" that includes all tab1 fields, and another called "tab2" that includes all tab2 fields.

Datatable date sorting dd/mm/yyyy issue

Update 2020: HTML Solution

Since HTML 5 is so much developed and almost all major browser supporting it. So now a much cleaner approach is to use HTML5 data attributes (maxx777 provided a PHP solution I am using the simple HTML). For non-numeric data as in our scenario, we can use data-sort or data-order attribute and assign a sortable value to it.

HTML

<td data-sort='YYYYMMDD'>DD/MM/YYYY</td>

Here is working HTML solution

jQuery Solution

Here is working jQuery solution.

jQuery.extend( jQuery.fn.dataTableExt.oSort, {
"date-uk-pre": function ( a ) {
    var ukDatea = a.split('/');
    return (ukDatea[2] + ukDatea[1] + ukDatea[0]) * 1;
},

"date-uk-asc": function ( a, b ) {
    return ((a < b) ? -1 : ((a > b) ? 1 : 0));
},

"date-uk-desc": function ( a, b ) {
    return ((a < b) ? 1 : ((a > b) ? -1 : 0));
}
} );
 

Add the above code to script and set the specific column with Date values with { "sType": "date-uk" } and others as null, see below:

$(document).ready(function() {
    $('#example').dataTable( {
        "aoColumns": [
            null,
            null,
            null,
            null,
            { "sType": "date-uk" },
            null
        ]
    });
    });

How to use font-family lato?

Please put this code in head section

<link href='http://fonts.googleapis.com/css?family=Lato:400,700' rel='stylesheet' type='text/css'>

and use font-family: 'Lato', sans-serif; in your css. For example:

h1 {
    font-family: 'Lato', sans-serif;
    font-weight: 400;
}

Or you can use manually also

Generate .ttf font from fontSquiral

and can try this option

    @font-face {
        font-family: "Lato";
        src: url('698242188-Lato-Bla.eot');
        src: url('698242188-Lato-Bla.eot?#iefix') format('embedded-opentype'),
        url('698242188-Lato-Bla.svg#Lato Black') format('svg'),
        url('698242188-Lato-Bla.woff') format('woff'),
        url('698242188-Lato-Bla.ttf') format('truetype');
        font-weight: normal;
        font-style: normal;
}

Called like this

body {
  font-family: 'Lato', sans-serif;
}

How to get Java Decompiler / JD / JD-Eclipse running in Eclipse Helios

JAD Decomplier plug-in for Eclipse version 3.x and 4.x.

update site: http://feeling.sourceforge.net/update

Steps:

  1. Open Eclipse IDE.
  2. Click Help->Install New software
  3. Paste above URL and give name as JAD.
  4. Select the Eclipse Class Decompiler
  5. Click on Next and accept agreements
  6. Install it.
  7. Restart Eclipse and check now.

org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15

I got similar error (org.aspectj.apache.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15) while using aspectj 1.8.13. Solution was to align all compilation into jdk 8 and being careful not to put aspectj library's (1.6.13 for instance) other versions to buildpath/classpath.

How can I have grep not print out 'No such file or directory' errors?

Errors like that are usually sent to the "standard error" stream, which you can pipe to a file or just make disappear on most commands:

grep pattern * -R -n 2>/dev/null

C++ String Declaring

In C++ you can declare a string like this:

#include <string>

using namespace std;

int main()
{
    string str1("argue2000"); //define a string and Initialize str1 with "argue2000"    
    string str2 = "argue2000"; // define a string and assign str2 with "argue2000"
    string str3;  //just declare a string, it has no value
    return 1;
}

How to print time in format: 2009-08-10 18:17:54.811

time.h defines a strftime function which can give you a textual representation of a time_t using something like:

#include <stdio.h>
#include <time.h>
int main (void) {
    char buff[100];
    time_t now = time (0);
    strftime (buff, 100, "%Y-%m-%d %H:%M:%S.000", localtime (&now));
    printf ("%s\n", buff);
    return 0;
}

but that won't give you sub-second resolution since that's not available from a time_t. It outputs:

2010-09-09 10:08:34.000

If you're really constrained by the specs and do not want the space between the day and hour, just remove it from the format string.

getActivity() returns null in Fragment function

Where do you call this function? If you call it in the constructor of Fragment, it will return null.

Just call getActivity() when the method onCreateView() is executed.

How to write and read java serialized objects into a file

Why not serialize the whole list at once?

FileOutputStream fout = new FileOutputStream("G:\\address.ser");
ObjectOutputStream oos = new ObjectOutputStream(fout);
oos.writeObject(MyClassList);

Assuming, of course, that MyClassList is an ArrayList or LinkedList, or another Serializable collection.

In the case of reading it back, in your code you ready only one item, there is no loop to gather all the item written.

How to make an HTTP get request with parameters

My preferred way is this. It handles the escaping and parsing for you.

WebClient webClient = new WebClient();
webClient.QueryString.Add("param1", "value1");
webClient.QueryString.Add("param2", "value2");
string result = webClient.DownloadString("http://theurl.com");

Freely convert between List<T> and IEnumerable<T>

Converting List<T> to IEnumerable<T>

List<T> implements IEnumerable<T> (and many other such as IList<T>, ICollection<T>) therefore there is no need to convert a List back to IEnumerable since it already a IEnumerable<T>.

Example:

public class Person
{
    public int Id { get; set; }
    public string Name { get; set; }
}

Person person1 = new Person() { Id = 1, Name = "Person 1" };
Person person2 = new Person() { Id = 2, Name = "Person 2" };
Person person3 = new Person() { Id = 3, Name = "Person 3" };

List<Person> people = new List<Person>() { person1, person2, person3 };

//Converting to an IEnumerable
IEnumerable<Person> IEnumerableList = people;

You can also use Enumerable.AsEnumerable() method

IEnumerable<Person> iPersonList = people.AsEnumerable();

Converting IEnumerable<T> to List<T>

IEnumerable<Person> OriginallyIEnumerable = new List<Person>() { person1, person2 };
List<Person> convertToList = OriginallyIEnumerable.ToList();

This is useful in Entity Framework.

How to checkout a specific Subversion revision from the command line?

It seems that you can use the repository browser. Click the revision button at top-right and change it to the revision you want. Then right-click your file in the browser and use 'Copy to working copy...' but change the filename it will check out, to avoid a clash.

How to select rows with NaN in particular column?

@qbzenker provided the most idiomatic method IMO

Here are a few alternatives:

In [28]: df.query('Col2 != Col2') # Using the fact that: np.nan != np.nan
Out[28]:
   Col1  Col2  Col3
1     0   NaN   0.0

In [29]: df[np.isnan(df.Col2)]
Out[29]:
   Col1  Col2  Col3
1     0   NaN   0.0

Change Spinner dropdown icon

Have you tried to define a custom background in xml? decreasing the Spinner background width which is doing your arrow look like that.

Define a layer-list with a rectangle background and your custom arrow icon:

    <?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <solid android:color="@color/color_white" />
            <corners android:radius="2.5dp" />
        </shape>
    </item>
    <item android:right="64dp">
         <bitmap android:gravity="right|center_vertical"  
             android:src="@drawable/custom_spinner_icon">
         </bitmap>
    </item>
</layer-list>

How to get the process ID to kill a nohup process?

If you are unaware of the PID, then first find it using TOP command

top -U userid

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND

You will get the PID using top, then perform the kill operation.

$ kill -9 <PID>

BitBucket - download source as ZIP

To Download Specific Branch - Go To Downloads from Left panel, Select Branches on Downloads page. It will list all Branches available. Download your desired branch in zip, gz, or bz2 format.

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DataSet panel (Report Data) in SSRS designer is gone

If you are working with SQL 2008 R2 then from View---->Report Data option at bottom

Multiple "order by" in LINQ

This should work for you:

var movies = _db.Movies.OrderBy(c => c.Category).ThenBy(n => n.Name)

Styling twitter bootstrap buttons

In Twitter Bootstrap bootstrap 3.0.0, Twitter button is flat. You can customize it from http://getbootstrap.com/customize. Button color, border radious etc.

Also you can find the HTML code and others functionality http://twitterbootstrap.org/bootstrap-css-buttons.

Bootstrap 2.3.2 button is gradient but 3.0.0 ( new release ) flat and looks more cool.

and also you can find to customize the entire bootstrap looks and style form this resources: http://twitterbootstrap.org/top-5-customizing-bootstrap-resources/

Running a CMD or BAT in silent mode

Use Advanced BAT to EXE Converter from http://www.battoexeconverter.com

This will allow you to embed any additional binaries with your batch file in to one stand alone completely silent EXE and its freeware

Difference between filter and filter_by in SQLAlchemy

It is a syntax sugar for faster query writing. Its implementation in pseudocode:

def filter_by(self, **kwargs):
    return self.filter(sql.and_(**kwargs))

For AND you can simply write:

session.query(db.users).filter_by(name='Joe', surname='Dodson')

btw

session.query(db.users).filter(or_(db.users.name=='Ryan', db.users.country=='England'))

can be written as

session.query(db.users).filter((db.users.name=='Ryan') | (db.users.country=='England'))

Also you can get object directly by PK via get method:

Users.query.get(123)
# And even by a composite PK
Users.query.get(123, 321)

When using get case its important that object can be returned without database request from identity map which can be used as cache(associated with transaction)

CSS3 transform: rotate; in IE9

Standard CSS3 rotate should work in IE9, but I believe you need to give it a vendor prefix, like so:

  -ms-transform: rotate(10deg);

It is possible that it may not work in the beta version; if not, try downloading the current preview version (preview 7), which is a later revision that the beta. I don't have the beta version to test against, so I can't confirm whether it was in that version or not. The final release version is definitely slated to support it.

I can also confirm that the IE-specific filter property has been dropped in IE9.

[Edit]
People have asked for some further documentation. As they say, this is quite limited, but I did find this page: http://css3please.com/ which is useful for testing various CSS3 features in all browsers.

But testing the rotate feature on this page in IE9 preview caused it to crash fairly spectacularly.

However I have done some independant tests using -ms-transform:rotate() in IE9 in my own test pages, and it is working fine. So my conclusion is that the feature is implemented, but has got some bugs, possibly related to setting it dynamically.

Another useful reference point for which features are implemented in which browsers is www.canIuse.com -- see http://caniuse.com/#search=rotation

[EDIT]
Reviving this old answer because I recently found out about a hack called CSS Sandpaper which is relevant to the question and may make things easier.

The hack implements support for the standard CSS transform for for old versions of IE. So now you can add the following to your CSS:

-sand-transform: rotate(10deg);

...and have it work in IE 6/7/8, without having to use the filter syntax. (of course it still uses the filter syntax behind the scenes, but this makes it a lot easier to manage because it's using similar syntax to other browsers)

How to commit and rollback transaction in sql server?

As per http://msdn.microsoft.com/en-us/library/ms188790.aspx

@@ERROR: Returns the error number for the last Transact-SQL statement executed.

You will have to check after each statement in order to perform the rollback and return.

Commit can be at the end.

HTH

how to set the default value to the drop down list control?

After your DataBind():

lstDepartment.SelectedIndex = 0;  //first item

or

lstDepartment.SelectedValue = "Yourvalue"

or 
//add error checking, just an example, FindByValue may return null
lstDepartment.Items.FindByValue("Yourvalue").Selected = true;

or
//add error checking, just an example, FindByText may return null
lstDepartment.Items.FindByText("Yourvalue").Selected = true;

How to delete a folder in C++?

This works for deleting all the directories and files within a directory.

#include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;
int main()
{
    cout << "Enter the DirectoryName to Delete : ";
    string directoryName;
    cin >> directoryName;
    string a = "rmdir /s /q " + directoryName;
    system(a.c_str());
    return 0;
}

"Initializing" variables in python?

You are asking to initialize four variables using a single float object, which of course is not iterable. You can do -

  1. grade_1, grade_2, grade_3, grade_4 = [0.0 for _ in range(4)]
  2. grade_1 = grade_2 = grade_3 = grade_4 = 0.0

Unless you want to initialize them with different values of course.

What does status=canceled for a resource mean in Chrome Developer Tools?

Another place we've encountered the (canceled) status is in a particular TLS certificate misconfiguration. If a site such as https://www.example.com is misconfigured such that the certificate does not include the www. but is valid for https://example.com, chrome will cancel this request and automatically redirect to the latter site. This is not the case for Firefox.

Currently valid example: https://www.pthree.org/

Express-js can't GET my static files, why?

if your setup

myApp
  |
  |__ public
  |     |
  |     |__  stylesheets
  |     |     |
  |     |     |__ style.css
  |     |
  |     |___ img
  |           |
  |           |__ logo.png
  |
  |__ app.js

then,
put in app.js

app.use('/static', express.static('public'));

and refer to your style.css: (in some .pug file):

link(rel='stylesheet', href='/static/stylesheets/style.css')

Declaring variables inside loops, good practice or bad practice?

Once upon a time (pre C++98); the following would break:

{
    for (int i=0; i<.; ++i) {std::string foo;}
    for (int i=0; i<.; ++i) {std::string foo;}
}

with the warning that i was already declared (foo was fine as that's scoped within the {}). This is likely the WHY people would first argue it's bad. It stopped being true a long time ago though.

If you STILL have to support such an old compiler (some people are on Borland) then the answer is yes, a case could be made to put the i out the loop, because not doing so makes it makes it "harder" for people to put multiple loops in with the same variable, though honestly the compiler will still fail, which is all you want if there's going to be a problem.

If you no longer have to support such an old compiler, variables should be kept to the smallest scope you can get them so that you not only minimise the memory usage; but also make understanding the project easier. It's a bit like asking why don't you have all your variables global. Same argument applies, but the scopes just change a bit.

How to open, read, and write from serial port in C?

For demo code that conforms to POSIX standard as described in Setting Terminal Modes Properly and Serial Programming Guide for POSIX Operating Systems, the following is offered.
This code should execute correctly using Linux on x86 as well as ARM (or even CRIS) processors.
It's essentially derived from the other answer, but inaccurate and misleading comments have been corrected.

This demo program opens and initializes a serial terminal at 115200 baud for non-canonical mode that is as portable as possible.
The program transmits a hardcoded text string to the other terminal, and delays while the output is performed.
The program then enters an infinite loop to receive and display data from the serial terminal.
By default the received data is displayed as hexadecimal byte values.

To make the program treat the received data as ASCII codes, compile the program with the symbol DISPLAY_STRING, e.g.

 cc -DDISPLAY_STRING demo.c

If the received data is ASCII text (rather than binary data) and you want to read it as lines terminated by the newline character, then see this answer for a sample program.


#define TERMINAL    "/dev/ttyUSB0"

#include <errno.h>
#include <fcntl.h> 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

int set_interface_attribs(int fd, int speed)
{
    struct termios tty;

    if (tcgetattr(fd, &tty) < 0) {
        printf("Error from tcgetattr: %s\n", strerror(errno));
        return -1;
    }

    cfsetospeed(&tty, (speed_t)speed);
    cfsetispeed(&tty, (speed_t)speed);

    tty.c_cflag |= (CLOCAL | CREAD);    /* ignore modem controls */
    tty.c_cflag &= ~CSIZE;
    tty.c_cflag |= CS8;         /* 8-bit characters */
    tty.c_cflag &= ~PARENB;     /* no parity bit */
    tty.c_cflag &= ~CSTOPB;     /* only need 1 stop bit */
    tty.c_cflag &= ~CRTSCTS;    /* no hardware flowcontrol */

    /* setup for non-canonical mode */
    tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
    tty.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
    tty.c_oflag &= ~OPOST;

    /* fetch bytes as they become available */
    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 1;

    if (tcsetattr(fd, TCSANOW, &tty) != 0) {
        printf("Error from tcsetattr: %s\n", strerror(errno));
        return -1;
    }
    return 0;
}

void set_mincount(int fd, int mcount)
{
    struct termios tty;

    if (tcgetattr(fd, &tty) < 0) {
        printf("Error tcgetattr: %s\n", strerror(errno));
        return;
    }

    tty.c_cc[VMIN] = mcount ? 1 : 0;
    tty.c_cc[VTIME] = 5;        /* half second timer */

    if (tcsetattr(fd, TCSANOW, &tty) < 0)
        printf("Error tcsetattr: %s\n", strerror(errno));
}


int main()
{
    char *portname = TERMINAL;
    int fd;
    int wlen;
    char *xstr = "Hello!\n";
    int xlen = strlen(xstr);

    fd = open(portname, O_RDWR | O_NOCTTY | O_SYNC);
    if (fd < 0) {
        printf("Error opening %s: %s\n", portname, strerror(errno));
        return -1;
    }
    /*baudrate 115200, 8 bits, no parity, 1 stop bit */
    set_interface_attribs(fd, B115200);
    //set_mincount(fd, 0);                /* set to pure timed read */

    /* simple output */
    wlen = write(fd, xstr, xlen);
    if (wlen != xlen) {
        printf("Error from write: %d, %d\n", wlen, errno);
    }
    tcdrain(fd);    /* delay for output */


    /* simple noncanonical input */
    do {
        unsigned char buf[80];
        int rdlen;

        rdlen = read(fd, buf, sizeof(buf) - 1);
        if (rdlen > 0) {
#ifdef DISPLAY_STRING
            buf[rdlen] = 0;
            printf("Read %d: \"%s\"\n", rdlen, buf);
#else /* display hex */
            unsigned char   *p;
            printf("Read %d:", rdlen);
            for (p = buf; rdlen-- > 0; p++)
                printf(" 0x%x", *p);
            printf("\n");
#endif
        } else if (rdlen < 0) {
            printf("Error from read: %d: %s\n", rdlen, strerror(errno));
        } else {  /* rdlen == 0 */
            printf("Timeout from read\n");
        }               
        /* repeat read to get full message */
    } while (1);
}

For an example of an efficient program that provides buffering of received data yet allows byte-by-byte handing of the input, then see this answer.


What's the yield keyword in JavaScript?

Fibonacci sequence generator using the yield keyword.

function* fibbonaci(){
    var a = -1, b = 1, c;
    while(1){
        c = a + b;
        a = b;
        b = c;
        yield c;
    }   
}

var fibonacciGenerator = fibbonaci();
fibonacciGenerator.next().value; // 0 
fibonacciGenerator.next().value; // 1
fibonacciGenerator.next().value; // 1
fibonacciGenerator.next().value; // 2 

How to delete shared preferences data from App in Android

Deleting Android Shared Preferences in one line :-)

context.getSharedPreferences("YOUR_PREFS", 0).edit().clear().commit();

Or apply for non-blocking asynchronous operation:

this.getSharedPreferences("YOUR_PREFS", 0).edit().clear().apply();

What does 'corrupted double-linked list' mean

I ran into this error in some code where someone was calling exit() in one thread about the same time as main() returned, so all the global/static constructors were being kicked off in two separate threads simultaneously.

This error also manifests as double free or corruption, or a segfault/sig11 inside exit() or inside malloc_consolidate, and likely others. The call stack for the malloc_consolidate crash may resemble:

#0  0xabcdabcd in malloc_consolidate () from /lib/libc.so.6
#1  0xabcdabcd in _int_free () from /lib/libc.so.6
#2  0xabcdabcd in operator delete (...)
#3  0xabcdabcd in operator delete[] (...)
(...)

I couldn't get it to exhibit this problem while running under valgrind.

How to wait in a batch script?

You'd better ping 127.0.0.1. Windows ping pauses for one second between pings so you if you want to sleep for 10 seconds, use

ping -n 11 127.0.0.1 > nul

This way you don't need to worry about unexpected early returns (say, there's no default route and the 123.45.67.89 is instantly known to be unreachable.)

Rails 4: assets not loading in production

For Rails 5, you should enable the follow config code:

config.public_file_server.enabled = true

By default, Rails 5 ships with this line of config:

config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?

Hence, you will need to set the environment variable RAILS_SERVE_STATIC_FILES to true.